Author Archives: Edward Fernandez

New AI-Powered Scam Detection Features to Help Protect You on Android

Posted by Lyubov Farafonova, Product Manager, Phone by Google; Alberto Pastor Nieto, Sr. Product Manager Google Messages and RCS Spam and Abuse

Google has been at the forefront of protecting users from the ever-growing threat of scams and fraud with cutting-edge technologies and security expertise for years. In 2024, scammers used increasingly sophisticated tactics and generative AI-powered tools to steal more than $1 trillion from mobile consumers globally, according to the Global Anti-Scam Alliance. And with the majority of scams now delivered through phone calls and text messages, we’ve been focused on making Android’s safeguards even more intelligent with powerful Google AI to help keep your financial information and data safe.

Today, we’re launching two new industry-leading AI-powered scam detection features for calls and text messages, designed to protect users from increasingly complex and damaging scams. These features specifically target conversational scams, which can often appear initially harmless before evolving into harmful situations.

To enhance our detection capabilities, we partnered with financial institutions around the world to better understand the latest advanced and most common scams their customers are facing. For example, users are experiencing more conversational text scams that begin innocently, but gradually manipulate victims into sharing sensitive data, handing over funds, or switching to other messaging apps. And more phone calling scammers are using spoofing techniques to hide their real numbers and pretend to be trusted companies.

Traditional spam protections are focused on protecting users before the conversation starts, and are less effective against these latest tactics from scammers that turn dangerous mid-conversation and use social engineering techniques. To better protect users, we invested in new, intelligent AI models capable of detecting suspicious patterns and delivering real-time warnings over the course of a conversation, all while prioritizing user privacy.

Scam Detection for messages

We’re building on our enhancements to existing Spam Protection in Google Messages that strengthen defenses against job and delivery scams, which are continuing to roll out to users. We’re now introducing Scam Detection to detect a wider range of fraudulent activities.

Scam Detection in Google Messages uses powerful Google AI to proactively address conversational scams by providing real-time detection even after initial messages are received. When the on-device AI detects a suspicious pattern in SMS, MMS, and RCS messages, users will now get a message warning of a likely scam with an option to dismiss or report and block the sender.

As part of the Spam Protection setting, Scam Detection on Google Messages is on by default and only applies to conversations with non-contacts. Your privacy is protected with Scam Detection in Google Messages, with all message processing remaining on-device. Your conversations remain private to you; if you choose to report a conversation to help reduce widespread spam, only sender details and recent messages with that sender are shared with Google and carriers. You can turn off Spam Protection, which includes Scam Detection, in your Google Messages at any time.

Scam Detection in Google Messages is launching in English first in the U.S., U.K. and Canada and will expand to more countries soon.

Scam Detection for calls

More than half of Americans reported receiving at least one scam call per day in 2024. To combat the rise of sophisticated conversational scams that deceive victims over the course of a phone call, we introduced Scam Detection late last year to U.S.-based English-speaking Phone by Google public beta users on Pixel phones.

We use AI models processed on-device to analyze conversations in real-time and warn users of potential scams. If a caller, for example, tries to get you to provide payment via gift cards to complete a delivery, Scam Detection will alert you through audio and haptic notifications and display a warning on your phone that the call may be a scam.

During our limited beta, we analyzed calls with Gemini Nano, Google’s built-in, on-device foundation model, on Pixel 9 devices and used smaller, robust on-device machine-learning models for Pixel 6+ users. Our testing showed that Gemini Nano outperformed other models, so as a result, we're currently expanding the availability of the beta to bring the most capable Scam Detection to all English-speaking Pixel 9+ users in the U.S.

Similar to Scam Detection in messaging, we built this feature to protect your privacy by processing everything on-device. Call audio is processed ephemerally and no conversation audio or transcription is recorded, stored on the device, or sent to Google or third parties. Scam Detection in Phone by Google is off by default to give users control over this feature, as phone call audio is more ephemeral compared to messages, which are stored on devices. Scam Detection only applies to calls that could potentially be scams, and is never used during calls with your contacts. If enabled, Scam Detection will beep at the start and during the call to notify participants the feature is on. You can turn off Scam Detection at any time, during an individual call or for all future calls.

According to our research and a Scam Detection beta user survey, these types of alerts have already helped people be more cautious on the phone, detect suspicious activity, and avoid falling victim to conversational scams.

Keeping Android users safe with the power of Google AI


We're committed to keeping Android users safe, and that means constantly evolving our defenses against increasingly sophisticated scams and fraud. Our investment in intelligent protection is having real-world impact for billions of users. Leviathan Security Group, a cybersecurity firm, conducted a funded evaluation of fraud protection features on a number of smartphones and found that Android smartphones, led by the Pixel 9 Pro, scored highest for built-in security features and anti-fraud efficacy1.

With AI-powered innovations like Scam Detection in Messages and Phone by Google, we're giving you more tools to stay one step ahead of bad actors. We're constantly working with our partners across the Android ecosystem to help bring new security features to even more users. Together, we’re always working to keep you safe on Android.

Notes

  1. Based on third-party research funded by Google LLC in Feb 2025 comparing the Pixel 9 Pro, iPhone 16 Pro, Samsung S24+ and Xiaomi 14 Ultra. Evaluation based on no-cost smartphone features enabled by default. Some features may not be available in all countries. ↩

New AI-Powered Scam Detection Features to Help Protect You on Android

Posted by Lyubov Farafonova, Product Manager, Phone by Google; Alberto Pastor Nieto, Sr. Product Manager Google Messages and RCS Spam and Abuse

Google has been at the forefront of protecting users from the ever-growing threat of scams and fraud with cutting-edge technologies and security expertise for years. In 2024, scammers used increasingly sophisticated tactics and generative AI-powered tools to steal more than $1 trillion from mobile consumers globally, according to the Global Anti-Scam Alliance. And with the majority of scams now delivered through phone calls and text messages, we’ve been focused on making Android’s safeguards even more intelligent with powerful Google AI to help keep your financial information and data safe.

Today, we’re launching two new industry-leading AI-powered scam detection features for calls and text messages, designed to protect users from increasingly complex and damaging scams. These features specifically target conversational scams, which can often appear initially harmless before evolving into harmful situations.

To enhance our detection capabilities, we partnered with financial institutions around the world to better understand the latest advanced and most common scams their customers are facing. For example, users are experiencing more conversational text scams that begin innocently, but gradually manipulate victims into sharing sensitive data, handing over funds, or switching to other messaging apps. And more phone calling scammers are using spoofing techniques to hide their real numbers and pretend to be trusted companies.

Traditional spam protections are focused on protecting users before the conversation starts, and are less effective against these latest tactics from scammers that turn dangerous mid-conversation and use social engineering techniques. To better protect users, we invested in new, intelligent AI models capable of detecting suspicious patterns and delivering real-time warnings over the course of a conversation, all while prioritizing user privacy.

Scam Detection for messages

We’re building on our enhancements to existing Spam Protection in Google Messages that strengthen defenses against job and delivery scams, which are continuing to roll out to users. We’re now introducing Scam Detection to detect a wider range of fraudulent activities.

Scam Detection in Google Messages uses powerful Google AI to proactively address conversational scams by providing real-time detection even after initial messages are received. When the on-device AI detects a suspicious pattern in SMS, MMS, and RCS messages, users will now get a message warning of a likely scam with an option to dismiss or report and block the sender.

As part of the Spam Protection setting, Scam Detection on Google Messages is on by default and only applies to conversations with non-contacts. Your privacy is protected with Scam Detection in Google Messages, with all message processing remaining on-device. Your conversations remain private to you; if you choose to report a conversation to help reduce widespread spam, only sender details and recent messages with that sender are shared with Google and carriers. You can turn off Spam Protection, which includes Scam Detection, in your Google Messages at any time.

Scam Detection in Google Messages is launching in English first in the U.S., U.K. and Canada and will expand to more countries soon.

Scam Detection for calls

More than half of Americans reported receiving at least one scam call per day in 2024. To combat the rise of sophisticated conversational scams that deceive victims over the course of a phone call, we introduced Scam Detection late last year to U.S.-based English-speaking Phone by Google public beta users on Pixel phones.

We use AI models processed on-device to analyze conversations in real-time and warn users of potential scams. If a caller, for example, tries to get you to provide payment via gift cards to complete a delivery, Scam Detection will alert you through audio and haptic notifications and display a warning on your phone that the call may be a scam.

During our limited beta, we analyzed calls with Gemini Nano, Google’s built-in, on-device foundation model, on Pixel 9 devices and used smaller, robust on-device machine-learning models for Pixel 6+ users. Our testing showed that Gemini Nano outperformed other models, so as a result, we're currently expanding the availability of the beta to bring the most capable Scam Detection to all English-speaking Pixel 9+ users in the U.S.

Similar to Scam Detection in messaging, we built this feature to protect your privacy by processing everything on-device. Call audio is processed ephemerally and no conversation audio or transcription is recorded, stored on the device, or sent to Google or third parties. Scam Detection in Phone by Google is off by default to give users control over this feature, as phone call audio is more ephemeral compared to messages, which are stored on devices. Scam Detection only applies to calls that could potentially be scams, and is never used during calls with your contacts. If enabled, Scam Detection will beep at the start and during the call to notify participants the feature is on. You can turn off Scam Detection at any time, during an individual call or for all future calls.

According to our research and a Scam Detection beta user survey, these types of alerts have already helped people be more cautious on the phone, detect suspicious activity, and avoid falling victim to conversational scams.

Keeping Android users safe with the power of Google AI


We're committed to keeping Android users safe, and that means constantly evolving our defenses against increasingly sophisticated scams and fraud. Our investment in intelligent protection is having real-world impact for billions of users. Leviathan Security Group, a cybersecurity firm, conducted a funded evaluation of fraud protection features on a number of smartphones and found that Android smartphones, led by the Pixel 9 Pro, scored highest for built-in security features and anti-fraud efficacy1.

With AI-powered innovations like Scam Detection in Messages and Phone by Google, we're giving you more tools to stay one step ahead of bad actors. We're constantly working with our partners across the Android ecosystem to help bring new security features to even more users. Together, we’re always working to keep you safe on Android.

Notes

  1. Based on third-party research funded by Google LLC in Feb 2025 comparing the Pixel 9 Pro, iPhone 16 Pro, Samsung S24+ and Xiaomi 14 Ultra. Evaluation based on no-cost smartphone features enabled by default. Some features may not be available in all countries. ↩

How we kept the Google Play & Android app ecosystems safe in 2024

Posted by Bethel Otuteye and Khawaja Shams (Android Security and Privacy Team), and Ron Aquino (Play Trust and Safety)

Android and Google Play comprise a vibrant ecosystem with billions of users around the globe and millions of helpful apps. Keeping this ecosystem safe for users and developers remains our top priority. However, like any flourishing ecosystem, it also attracts its share of bad actors. That’s why every year, we continue to invest in more ways to protect our community and fight bad actors, so users can trust the apps they download from Google Play and developers can build thriving businesses.

Last year, those investments included AI-powered threat detection, stronger privacy policies, supercharged developer tools, new industry-wide alliances, and more. As a result, we prevented 2.36 million policy-violating apps from being published on Google Play and banned more than 158,000 bad developer accounts that attempted to publish harmful apps.

But that was just the start. For more, take a look at our recent highlights from 2024:

Google’s advanced AI: helping make Google Play a safer place



To keep out bad actors, we have always used a combination of human security experts and the latest threat-detection technology. In 2024, we used Google’s advanced AI to improve our systems’ ability to proactively identify malware, enabling us to detect and block bad apps more effectively. It also helps us streamline review processes for developers with a proven track record of policy compliance. Today, over 92% of our human reviews for harmful apps are AI-assisted, allowing us to take quicker and more accurate action to help prevent harmful apps from becoming available on Google Play.

That’s enabled us to stop more bad apps than ever from reaching users through the Play Store, protecting users from harmful or malicious apps before they can cause any damage.

Working with developers to enhance security and privacy on Google Play

To protect user privacy, we’re working with developers to reduce unnecessary access to sensitive data. In 2024, we prevented 1.3 million apps from getting excessive or unnecessary access to sensitive user data. We also required apps to be more transparent about how they handle user information by launching new developer requirements and a new “Data deletion” option for apps that support user accounts and data collection. This helps users manage their app data and understand the app’s deletion practices, making it easier for Play users to delete data collected from third-party apps.

We also worked to ensure that apps use the strongest and most up-to-date privacy and security capabilities Android has to offer. Every new version of Android introduces new security and privacy features, and we encourage developers to embrace these advancements as soon as possible. As a result of partnering closely with developers, over 91% of app installs on the Google Play Store now use the latest protections of Android 13 or newer.

Safeguarding apps from scams and fraud is an ongoing battle for developers. The Play Integrity API allows developers to check if their apps have been tampered with or are running in potentially compromised environments, helping them to prevent abuse like fraud, bots, cheating, and data theft. Play Integrity API and Play’s automatic protection helps developers ensure that users are using the official Play version of their app with the latest security updates. Apps using Play integrity features are seeing 80% lower usage from unverified and untrusted sources on average.

We’re also constantly working to improve the safety of apps on Play at scale, such as with the Google Play SDK Index. This tool offers insights and data to help developers make more informed decisions about the safety of an SDK. Last year, in addition to adding 80 SDKs to the index, we also worked closely with SDK and app developers to address potential SDK security and privacy issues, helping to build safer and more secure apps for Google Play.

Google Play’s multi-layered protections against bad apps



To create a trusted experience for everyone on Google Play, we use our SAFE principles as a guide, incorporating multi-layered protections that are always evolving to help keep Google Play safe. These protections start with the developers themselves, who play a crucial role in building secure apps. We provide developers with best-in-class tools, best practices, and on-demand training resources for building safe, high-quality apps. Every app undergoes rigorous review and testing, with only approved apps allowed to appear in the Play Store. Before a user downloads an app from Play, users can explore its user reviews, ratings, and Data safety section on Google Play to help them make an informed decision. And once installed, Google Play Protect, Android’s built-in security protection, helps to shield their Android device by continuously scanning for malicious app behavior.

Enhancing Google Play Protect to help keep users safe on Android



While the Play Store offers best-in-class security, we know it’s not the only place users download Android apps – so it’s important that we also defend Android users from more generalized mobile threats. To do this in an open ecosystem, we’ve invested in sophisticated, real-time defenses that protect against scams, malware, and abusive apps. These intelligent security measures help to keep users, user data, and devices safe, even if apps are installed from various sources with varying levels of security.


Google Play Protect automatically scans every app on Android devices with Google Play Services, no matter the download source. This built-in protection, enabled by default, provides crucial security against malware and unwanted software. Google Play Protect scans more than 200 billion apps daily and performs real-time scanning at the code-level on novel apps to combat emerging and hidden threats, like polymorphic malware. In 2024, Google Play Protect’s real-time scanning identified more than 13 million new malicious apps from outside Google Play1.

Google Play Protect is always evolving to combat new threats and protect users from harmful apps that can lead to scams and fraud. Here are some of the new improvements that are now available globally on Android devices with Google Play Services:

  • Reminder notifications in Chrome on Android to re-enable Google Play Protect: According to our research, more than 95 percent of app installations from major malware families that exploit sensitive permissions highly correlated to financial fraud came from Internet-sideloading sources like web browsers, messaging apps, or file managers. To help users stay protected when browsing the web, Chrome will now display a reminder notification to re-enable Google Play Protect if it has been turned off.
  • Additional protection against social engineering attacks: Scammers may manipulate users into disabling Play Protect during calls to download malicious Internet-sideloaded apps. To prevent this, the Play Protect app scanning toggle is now temporarily disabled during phone or video calls. This safeguard is enabled by default during traditional phone calls as well as during voice and video calls in popular third-party apps.
  • Automatically revoking app permissions for potentially dangerous apps: Since Android 11, we’ve taken a proactive approach to data privacy by automatically resetting permissions for apps that users haven't used in a while. This ensures apps can only access the data they truly need, and users can always grant permissions back if necessary. To further enhance security, Play Protect now automatically revokes permissions for potentially harmful apps, limiting their access to sensitive data like storage, photos, and camera. Users can restore app permissions at any time, with a confirmation step for added security.

Google Play Protect’s enhanced fraud protection pilot analyzes and automatically blocks the installation of apps that may use sensitive permissions frequently abused for financial fraud when the user attempts to install the app from an Internet-sideloading source (web browsers, messaging apps, or file managers).

Building on the success of our initial pilot in partnership with the Cyber Security Agency of Singapore (CSA), additional enhanced fraud protection pilots are now active in nine regions – Brazil, Hong Kong, India, Kenya, Nigeria, Philippines, South Africa, Thailand, and Vietnam.

In 2024, Google Play Protect’s enhanced fraud protection pilots have shielded 10 million devices from over 36 million risky installation attempts, encompassing over 200,000 unique apps.

By piloting these new protections, we can proactively combat emerging threats and refine our solutions to thwart scammers and their increasingly sophisticated fraud attempts. We look forward to continuing to partner with governments, ecosystem partners, and other stakeholders to improve user protections.

App badging to help users find apps they can trust at a glance on Google Play

In 2024, we introduced a new badge for government developers to help users around the world identify official government apps. Government apps are often targets of impersonation due to the highly sensitive nature of the data users provide, giving bad actors the ability to steal identities and commit financial fraud. Badging verified government apps is an important step in helping connect people with safe, high-quality, useful, and relevant experiences. We partner closely with global governments and are already exploring ways to build on this work.

We also recently introduced a new badge to help Google Play users discover VPN apps that take extra steps to demonstrate their strong commitment to security. We allow developers who adhere to Play safety and security guidelines and have passed an additional independent Mobile Application Security Assessment (MASA) to display a dedicated badge in the Play Store to highlight their increased commitment to safety.

Collaborating to advance app security standards

In addition to our partnerships with governments, developers, and other stakeholders, we also worked with our industry peers to protect the entire app ecosystem for everyone. The App Defense Alliance, in partnership with fellow steering committee members Microsoft and Meta, recently launched the ADA Application Security Assessment (ASA) v1.0, a new standard to help developers build more secure mobile, web, and cloud applications. This standard provides clear guidance on protecting sensitive data, defending against cyberattacks, and ultimately, strengthening user trust. This marks a significant step forward in establishing industry-wide security best practices for application development.

All developers are encouraged to review and comply with the new mobile security standard. You’ll see this standard in action for all carrier apps pre-installed on future Pixel phone models.

Looking ahead


This year, we’ll continue to protect the Android and Google Play ecosystem, building on these tools and resources in response to user and developer feedback and the changing landscape. As always, we’ll keep empowering developers to build safer apps more easily, streamline their policy experience, and protect their businesses and users from bad actors.

1 Based on Google Play Protect 2024 internal data.

Android enhances theft protection with Identity Check and expanded features

Posted by Jianing Sandra Guo, Product Manager, Android, Nataliya Stanetsky, Staff Program Manager, Android

Today, people around the world rely on their mobile devices to help them stay connected with friends and family, manage finances, keep track of healthcare information and more – all from their fingertips. But a stolen device in the wrong hands can expose sensitive data, leaving you vulnerable to identity theft, financial fraud and privacy breaches.

This is why we recently launched Android theft protection, a comprehensive suite of features designed to protect you and your data at every stage – before, during, and after device theft. As part of our commitment to help you stay safe on Android, we’re expanding and enhancing these features to deliver even more robust protection to more users around the world.

Identity Check rolling out to Pixel and Samsung One UI 7 devices

We’re officially launching Identity Check, first on Pixel and Samsung Galaxy devices eligible for One UI 71, to provide better protection for your critical account and device settings. When you turn on Identity Check, your device will require explicit biometric authentication to access certain sensitive resources when you’re outside of trusted locations. Identity Check also enables enhanced protection for Google Accounts on all supported devices and additional security for Samsung Accounts on One UI 7 eligible Galaxy devices, making it much more difficult for an unauthorized attacker to take over accounts signed in on the device.

As part of enabling Identity Check, you can designate one or more trusted locations. When you’re outside of these trusted places, biometric authentication will be required to access critical account and device settings, like changing your device PIN or biometrics, disabling theft protection, or accessing Passkeys.

Identity Check gives you more peace of mind that your most sensitive device assets are protected against unauthorized access, even if a thief or bad actor manages to learn your device PIN.

Identity Check is rolling out now to Pixel devices with Android 15 and will be available on One UI 7 eligible Galaxy devices in the coming weeks. It will roll out to supported Android devices from other manufacturers later this year.

Theft Detection Lock: expanding AI-powered protection to more users

One of the top theft protection features introduced last year was Theft Detection Lock, which uses an on-device AI-powered algorithm to help detect when your phone may be forcibly taken from you. If the machine learning algorithm detects a potential theft attempt on your unlocked device, it locks your screen to keep thieves out.

Theft Detection Lock is now fully rolled out to Android 10+ phones2 around the world.

Protecting your Android device from theft

We're collaborating with the GSMA and industry experts to combat mobile device theft by sharing information, tools and prevention techniques. Stay tuned for an upcoming GSMA white paper, developed in partnership with the mobile industry, with more information on protecting yourself and your organization from device theft.

With the addition of Identity Check and the ongoing enhancements to our existing features, Android offers a robust and comprehensive set of tools to protect your devices and your data from theft. We’re dedicated to providing you with peace of mind, knowing your personal information is safe and secure.

You can turn on the new Android theft features by clicking here on a supported Android device. Learn more about our theft protection features by visiting our help center.

Notes

  1. Timing, availability and feature names may vary in One UI 7. ↩

  2. With the exclusion for Android Go smartphones ↩

Safer with Google: New intelligent, real-time protections on Android to keep you safe

Posted by Lyubov Farafonova, Product Manager and Steve Kafka, Group Product Manager, Android

User safety is at the heart of everything we do at Google. Our mission to make technology helpful for everyone means building features that protect you while keeping your privacy top of mind. From Gmail’s defenses that stop more than 99.9% of spam, phishing and malware, to Google Messages’ advanced security that protects users from 2 billion suspicious messages a month and beyond, we're constantly developing and expanding protection features that help keep you safe.

We're introducing two new real-time protection features that enhance your safety, all while safeguarding your privacy: Scam Detection in Phone by Google to protect you from scams and fraud, and Google Play Protect live threat detection with real-time alerts to protect you from malware and dangerous apps.

These new security features are available first on Pixel, and are coming soon to more Android devices.

More intelligent AI-powered protection against scams

Scammers steal over $1 trillion dollars a year from people, and phone calls are their favorite way to do it. Even more alarming, scam calls are evolving, becoming increasingly more sophisticated, damaging and harder to identify. That’s why we’re using the best of Google AI to identify and stop scams before they can do harm with Scam Detection.

Real-time protection, built with your privacy in mind.

  • Real-time defense, right on your device: Scam Detection uses powerful on-device AI to notify you of a potential scam call happening in real-time by detecting conversation patterns commonly associated with scams. For example, if a caller claims to be from your bank and asks you to urgently transfer funds due to an alleged account breach, Scam Detection will process the call to determine whether the call is likely spam and, if so, can provide an audio and haptic alert and visual warning that the call may be a scam.
  • Private by design, you’re always in control: We’ve built Scam Detection to protect your privacy and ensure you’re always in control of your data. Scam Detection is off by default, and you can decide whether you want to activate it for future calls. At any time, you can turn it off for all calls in the Phone app Settings, or during a particular call. The AI detection model and processing are fully on-device, which means that no conversation audio or transcription is stored on the device, sent to Google servers or anywhere else, or retrievable after the call.
  • Cutting-edge AI protection, now on more Pixel phones: Gemini Nano, our advanced on-device AI model, powers Scam Detection on Pixel 9 series devices. As part of our commitment to bring powerful AI features to even more devices, this AI-powered protection is available to Pixel 6+ users thanks to other robust Google on-device machine learning models.

We’re now rolling out Scam Detection to English-speaking Phone by Google public beta users in the U.S. with a Pixel 6 or newer device.

To provide feedback on your experience, please click on Phone by Google App -> Menu -> Help & Feedback -> Send Feedback. We look forward to learning from this beta and your feedback, and we’ll share more about Scam Detection in the months ahead.

More real-time alerts to protect you from bad apps

Google Play Protect works non-stop to protect you in real-time from malware and unsafe apps. Play Protect analyzes behavioral signals related to the use of sensitive permissions and interactions with other apps and services.

With live threat detection, if a harmful app is found, you'll now receive a real-time alert, allowing you to take immediate action to protect your device. By looking at actual activity patterns of apps, live threat detection can now find malicious apps that try extra hard to hide their behavior or lie dormant for a time before engaging in suspicious activity.

At launch, live threat detection will focus on stalkerware, code that may collect personal or sensitive data for monitoring purposes without user consent, and we will explore expanding its detection to other types of harmful apps in the future. All of this protection happens on your device in a privacy preserving way through Private Compute Core, which allows us to protect users without collecting data.

Live threat detection with real-time alerts in Google Play Protect are now available on Pixel 6+ devices and will be coming to additional phone makers in the coming months.

5 new protections on Google Messages to help keep you safe

Posted by Jan Jedrzejowicz, Director of Product, Android and Business Communications; Alberto Pastor Nieto, Sr. Product Manager Google Messages and RCS Spam and Abuse; Stephan Somogyi, Product Lead, User Protection; Branden Archer, Software Engineer

Every day, over a billion people use Google Messages to communicate. That’s why we’ve made security a top priority, building in powerful on-device, AI-powered filters and advanced security that protects users from 2 billion suspicious messages a month. With end-to-end encrypted1 RCS conversations, you can communicate privately with other Google Messages RCS users. And we’re not stopping there. We're committed to constantly developing new controls and features to make your conversations on Google Messages even more secure and private.

As part of cybersecurity awareness month, we're sharing five new protections to help keep you safe while using Google Messages on Android:

  1. Enhanced detection protects you from package delivery and job scams. Google Messages is adding new protections against scam texts that may seem harmless at first but can eventually lead to fraud. For Google Messages beta users2, we’re rolling out enhanced scam detection, with improved analysis of scammy texts, starting with a focus on package delivery and job seeking messages. When Google Messages suspects a potential scam text, it will automatically move the message into your spam folder or warn you. Google Messages uses on-device machine learning models to classify these scams, so your conversations stay private and the content is never sent to Google unless you report spam. We’re rolling this enhancement out now to Google Messages beta users who have spam protection enabled.
  2. Intelligent warnings alert you about potentially dangerous links. In the past year, we’ve been piloting more protections for Google Messages users when they receive text messages with potentially dangerous links. In India, Thailand, Malaysia and Singapore, Google Messages warns users when they get a link from unknown senders and blocks messages with links from suspicious senders. We’re in the process of expanding this feature globally later this year.
  3. Controls to turn off messages from unknown international senders. In some cases, scam text messages come from international numbers. Soon, you will be able to automatically hide messages from international senders who are not existing contacts so you don’t have to interact with them. If enabled, messages from international non-contacts will automatically be moved to the “Spam & blocked” folder. This feature will roll out first as a pilot in Singapore later this year before we look at expanding to more countries.
  4. Sensitive Content Warnings give you control over seeing and sending images that may contain nudity. At Google, we aim to provide users with a variety of ways to protect themselves against unwanted content, while keeping them in control of their data. This is why we’re introducing Sensitive Content Warnings for Google Messages.

    Sensitive Content Warnings is an optional feature that blurs images that may contain nudity before viewing, and then prompts with a “speed bump” that contains help-finding resources and options, including to view the content. When the feature is enabled, and an image that may contain nudity is about to be sent or forwarded, it also provides a speed bump to remind users of the risks of sending nude imagery and preventing accidental shares.

    All of this happens on-device to protect your privacy and keep end-to-end encrypted message content private to only sender and recipient. Sensitive Content Warnings doesn’t allow Google access to the contents of your images, nor does Google know that nudity may have been detected. This feature is opt-in for adults, managed via Android Settings, and is opt-out for users under 18 years of age. Sensitive Content Warnings will be rolling out to Android 9+ devices including Android Go devices3 with Google Messages in the coming months.
  5. More confirmation about who you’re messaging. To help you avoid sophisticated messaging threats where an attacker tries to impersonate one of your contacts, we’re working to add a contact verifying feature to Android. This new feature will allow you to verify your contacts' public keys so you can confirm you’re communicating with the person you intend to message. We’re creating a unified system for public key verification across different apps, which you can verify through QR code scanning or number comparison. This feature will be launching next year for Android 9+ devices, with support for messaging apps including Google Messages.

    These are just some of the new and upcoming features that you can use to better protect yourself when sending and receiving messages. Download Google Messages from the Google Play Store to enjoy these protections and controls and learn more about Google Messages here.

    Notes

    1. End-to-end encryption is currently available between Google Messages users. Availability of RCS varies by region and carrier. ↩

    2. Availability of features may vary by market and device. Sign up for beta testing and a data plan may be required.  ↩

    3. Requires 2 GB of RAM. ↩

Bringing new theft protection features to Android users around the world

Posted by Jianing Sandra Guo, Product Manager and Nataliya Stanetsky, Staff Program Manager, Android

Janine Roberta Ferreira was driving home from work in São Paulo when she stopped at a traffic light. A man suddenly appeared and broke the window of her unlocked car, grabbing her phone. She struggled with him for a moment before he wrestled the phone away and ran off. The incident left her deeply shaken. Not only was she saddened at the loss of precious data, like pictures of her nephew, but she also felt vulnerable knowing her banking information was on her phone that was just stolen by a thief.

Situations like Janine’s highlighted the need for a comprehensive solution to phone theft that exceeded existing tools on any platform. Phone theft is a widespread concern in many countries – 97 phones are robbed or stolen every hour in Brazil. The GSM Association reports millions of devices stolen every year, and the numbers continue to grow.

With our phones becoming increasingly central to storing sensitive data, like payment information and personal details, losing one can be an unsettling experience. That’s why we developed and thoroughly beta tested, a full suite of features designed to protect you and your data at every stage – before, during, and after device theft.

These advanced theft protection features are now available to users around the world through Android 15 and a Google Play Services update (Android 10+ devices).

AI-powered protection for your device the moment it is stolen

Theft Detection Lock uses powerful AI to proactively protect you at the moment of a theft attempt. By using on-device machine learning, Theft Detection Lock is able to analyze various device signals to detect potential theft attempts. If the algorithm detects a potential theft attempt on your unlocked device, it locks your screen to keep thieves out.

To protect your sensitive data if your phone is stolen, Theft Detection Lock uses device sensors to identify theft attempts. We’re working hard to bring this feature to as many devices as possible. This feature is rolling out gradually to ensure compatibility with various devices, starting today with Android devices that cover 90% of active users worldwide. Check your theft protection settings page periodically to see if your device is currently supported.

In addition to Theft Detection Lock, Offline Device Lock protects you if a thief tries to take your device offline to extract data or avoid a remote wipe via Android’s Find My Device. If an unlocked device goes offline for prolonged periods, this feature locks the screen to ensure your phone can’t be used in the hands of a thief.

If your Android device does become lost or stolen, Remote Lock can quickly help you secure it. Even if you can’t remember your Google account credentials in the moment of theft, you can use any device to visit Android.com/lock and lock your phone with just a verified phone number. Remote Lock secures your device while you regain access through Android’s Find My Device – which lets you secure, locate or remotely wipe your device. As a security best practice, we always recommend backing up your device on a continuous basis, so remotely wiping your device is not an issue.

These features are now available on most Android 10+ devices1 via a Google Play Services update and must be enabled in settings.

Advanced security to deter theft before it happens

Android 15 introduces new security features to deter theft before it happens by making it harder for thieves to access sensitive settings, apps, or reset your device for resale:

  • Changes to sensitive settings like Find My Device now require your PIN, password, or biometric authentication.
  • Multiple failed login attempts, which could be a sign that a thief is trying to guess your password, will lock down your device, preventing unauthorized access.
  • And enhanced factory reset protection makes it even harder for thieves to reset your device without your Google account credentials, significantly reducing its resale value and protecting your data.

Later this year, we’ll launch Identity Check, an opt-in feature that will add an extra layer of protection by requiring biometric authentication when accessing critical Google account and device settings, like changing your PIN, disabling theft protection, or accessing Passkeys from an untrusted location. This helps prevent unauthorized access even if your device PIN is compromised.

Real-world protection for billions of Android users

By integrating advanced technology like AI and biometric authentication, we're making Android devices less appealing targets for thieves to give you greater peace of mind. These theft protection features are just one example of how Android is working to provide real-world protection for everyone. We’re dedicated to working with our partners around the world to continuously improve Android security and help you and your data stay safe.

You can turn on the new Android theft features by clicking here on a supported Android device. Learn more about our theft protection features by visiting our help center.

Notes

  1. Android Go smartphones, tablets and wearables are not supported ↩

Pixel’s Proactive Approach to Security: Addressing Vulnerabilities in Cellular Modems

Posted by Sherk Chung, Stephan Chen, Pixel team, and Roger Piqueras Jover, Ivan Lozano, Android team

Pixel phones have earned a well-deserved reputation for being security-conscious. In this blog, we'll take a peek under the hood to see how Pixel mitigates common exploits on cellular basebands.

Smartphones have become an integral part of our lives, but few of us think about the complex software that powers them, especially the cellular baseband – the processor on the device responsible for handling all cellular communication (such as LTE, 4G, and 5G). Most smartphones use cellular baseband processors with tight performance constraints, making security hardening difficult. Security researchers have increasingly exploited this attack vector and routinely demonstrated the possibility of exploiting basebands used in popular smartphones.

The good news is that Pixel has been deploying security hardening mitigations in our basebands for years, and Pixel 9 represents the most hardened baseband we've shipped yet. Below, we’ll dive into why this is so important, how specifically we’ve improved security, and what this means for our users.

The Cellular Baseband

The cellular baseband within a smartphone is responsible for managing the device's connectivity to cellular networks. This function inherently involves processing external inputs, which may originate from untrusted sources. For instance, malicious actors can employ false base stations to inject fabricated or manipulated network packets. In certain protocols like IMS (IP Multimedia Subsystem), this can be executed remotely from any global location using an IMS client.

The firmware within the cellular baseband, similar to any software, is susceptible to bugs and errors. In the context of the baseband, these software vulnerabilities pose a significant concern due to the heightened exposure of this component within the device's attack surface. There is ample evidence demonstrating the exploitation of software bugs in modem basebands to achieve remote code execution, highlighting the critical risk associated with such vulnerabilities.

The State of Baseband Security

Baseband security has emerged as a prominent area of research, with demonstrations of software bug exploitation featuring in numerous security conferences. Many of these conferences now also incorporate training sessions dedicated to baseband firmware emulation, analysis, and exploitation techniques.

Recent reports by security researchers have noted that most basebands lack exploit mitigations commonly deployed elsewhere and considered best practices in software development. Mature software hardening techniques that are commonplace in the Android operating system, for example, are often absent from cellular firmwares of many popular smartphones.

There are clear indications that exploit vendors and cyber-espionage firms abuse these vulnerabilities to breach the privacy of individuals without their consent. For example, 0-day exploits in the cellular baseband are being used to deploy the Predator malware in smartphones. Additionally, exploit marketplaces explicitly list baseband exploits, often with relatively low payouts, suggesting a potential abundance of such vulnerabilities. These vulnerabilities allow attackers to gain unauthorized access to a device, execute arbitrary code, escalate privileges, or extract sensitive information.

Recognizing these industry trends, Android and Pixel have proactively updated their Vulnerability Rewards Program in recent years, placing a greater emphasis on identifying and addressing exploitable bugs in connectivity firmware.

Building a Fortress: Proactive Defenses in the Pixel Modem

In response to the rising threat of baseband security attacks, Pixel has incrementally incorporated many of the following proactive defenses over the years, with the Pixel 9 phones (Pixel 9, Pixel 9 Pro, Pixel 9 Pro XL and Pixel 9 Pro Fold) showcasing the latest features:

  • Bounds Sanitizer: Buffer overflows occur when a bug in code allows attackers to cram too much data into a space, causing it to spill over and potentially corrupt other data or execute malicious code. Bounds Sanitizer automatically adds checks around a specific subset of memory accesses to ensure that code does not access memory outside of designated areas, preventing memory corruption.
  • Integer Overflow Sanitizer: Numbers matter, and when they get too large an “overflow” can cause them to be incorrectly interpreted as smaller values. The reverse can happen as well, a number can overflow in the negative direction as well and be incorrectly interpreted as a larger value. These overflows can be exploited by attackers to cause unexpected behavior. Integer Overflow Sanitizer adds checks around these calculations to eliminate the risk of memory corruption from this class of vulnerabilities.
  • Stack Canaries: Stack canaries are like tripwires set up to ensure code executes in the expected order. If a hacker tries to exploit a vulnerability in the stack to change the flow of execution without being mindful of the canary, the canary "trips," alerting the system to a potential attack.
  • Control Flow Integrity (CFI): Similar to stack canaries, CFI makes sure code execution is constrained along a limited number of paths. If an attacker tries to deviate from the allowed set of execution paths, CFI causes the modem to restart rather than take the unallowed execution path.
  • Auto-Initialize Stack Variables: When memory is designated for use, it’s not normally initialized in C/C+ as it is expected the developer will correctly set up the allocated region. When a developer fails to handle this correctly, the uninitialized values can leak sensitive data or be manipulated by attackers to gain code execution. Pixel phones automatically initialize stack variables to zero, preventing this class of vulnerabilities for stack data.

We also leverage a number of bug detection tools, such as address sanitizer, during our testing process. This helps us identify software bugs and patch them prior to shipping devices to our users.

The Pixel Advantage: Combining Protections for Maximum Security

Security hardening is difficult and our work is never done, but when these security measures are combined, they significantly increase Pixel 9’s resilience to baseband attacks.

Pixel's proactive approach to security demonstrates a commitment to protecting its users across the entire software stack. Hardening the cellular baseband against remote attacks is just one example of how Pixel is constantly working to stay ahead of the curve when it comes to security.

Special thanks to our colleagues who supported our cellular baseband hardening efforts: Dominik Maier, Shawn Yang, Sami Tolvanen, Pirama Arumuga Nainar, Stephen Hines, Kevin Deus, Xuan Xing, Eugene Rodionov, Stephan Somogyi, Wes Johnson, Suraj Harjani, Morgan Shen, Valery Wu, Clint Chen, Cheng-Yi He, Estefany Torres, Hungyen Weng, Jerry Hung, Sherif Hanna

Eliminating Memory Safety Vulnerabilities at the Source

Posted by Jeff Vander Stoep - Android team, and Alex Rebert - Security Foundations

Memory safety vulnerabilities remain a pervasive threat to software security. At Google, we believe the path to eliminating this class of vulnerabilities at scale and building high-assurance software lies in Safe Coding, a secure-by-design approach that prioritizes transitioning to memory-safe languages.

This post demonstrates why focusing on Safe Coding for new code quickly and counterintuitively reduces the overall security risk of a codebase, finally breaking through the stubbornly high plateau of memory safety vulnerabilities and starting an exponential decline, all while being scalable and cost-effective.

We’ll also share updated data on how the percentage of memory safety vulnerabilities in Android dropped from 76% to 24% over 6 years as development shifted to memory safe languages.

Counterintuitive results

Consider a growing codebase primarily written in memory-unsafe languages, experiencing a constant influx of memory safety vulnerabilities. What happens if we gradually transition to memory-safe languages for new features, while leaving existing code mostly untouched except for bug fixes?

We can simulate the results. After some years, the code base has the following makeup1 as new memory unsafe development slows down, and new memory safe development starts to take over:

In the final year of our simulation, despite the growth in memory-unsafe code, the number of memory safety vulnerabilities drops significantly, a seemingly counterintuitive result not seen with other strategies:

This reduction might seem paradoxical: how is this possible when the quantity of new memory unsafe code actually grew?

The math

The answer lies in an important observation: vulnerabilities decay exponentially. They have a half-life. The distribution of vulnerability lifetime follows an exponential distribution given an average vulnerability lifetime λ:

A large-scale study of vulnerability lifetimes2 published in 2022 in Usenix Security confirmed this phenomenon. Researchers found that the vast majority of vulnerabilities reside in new or recently modified code:

This confirms and generalizes our observation, published in 2021, that the density of Android’s memory safety bugs decreased with the age of the code, primarily residing in recent changes.

This leads to two important takeaways:

  • The problem is overwhelmingly with new code, necessitating a fundamental change in how we develop code.
  • Code matures and gets safer with time, exponentially, making the returns on investments like rewrites diminish over time as code gets older.

For example, based on the average vulnerability lifetimes, 5-year-old code has a 3.4x (using lifetimes from the study) to 7.4x (using lifetimes observed in Android and Chromium) lower vulnerability density than new code.

In real life, as with our simulation, when we start to prioritize prevention, the situation starts to rapidly improve.

In practice on Android

The Android team began prioritizing transitioning new development to memory safe languages around 2019. This decision was driven by the increasing cost and complexity of managing memory safety vulnerabilities. There’s much left to do, but the results have already been positive. Here’s the big picture in 2024, looking at total code:


Despite the majority of code still being unsafe (but, crucially, getting progressively older), we’re seeing a large and continued decline in memory safety vulnerabilities. The results align with what we simulated above, and are even better, potentially as a result of our parallel efforts to improve the safety of our memory unsafe code. We first reported this decline in 2022, and we continue to see the total number of memory safety vulnerabilities dropping3. Note that the data for 2024 is extrapolated to the full year (represented as 36, but currently at 27 after the September security bulletin).

The percent of vulnerabilities caused by memory safety issues continues to correlate closely with the development language that’s used for new code. Memory safety issues, which accounted for 76% of Android vulnerabilities in 2019, and are currently 24% in 2024, well below the 70% industry norm, and continuing to drop.

As we noted in a previous post, memory safety vulnerabilities tend to be significantly more severe, more likely to be remotely reachable, more versatile, and more likely to be maliciously exploited than other vulnerability types. As the number of memory safety vulnerabilities have dropped, the overall security risk has dropped along with it.

Evolution of memory safety strategies

Over the past decades, the industry has pioneered significant advancements to combat memory safety vulnerabilities, with each generation of advancements contributing valuable tools and techniques that have tangibly improved software security. However, with the benefit of hindsight, it’s evident that we have yet to achieve a truly scalable and sustainable solution that achieves an acceptable level of risk:

1st generation: reactive patching. The initial focus was mainly on fixing vulnerabilities reactively. For problems as rampant as memory safety, this incurs ongoing costs on the business and its users. Software manufacturers have to invest significant resources in responding to frequent incidents. This leads to constant security updates, leaving users vulnerable to unknown issues, and frequently albeit temporarily vulnerable to known issues, which are getting exploited ever faster.

2nd generation: proactive mitigating. The next approach consisted of reducing risk in vulnerable software, including a series of exploit mitigation strategies that raised the costs of crafting exploits. However, these mitigations, such as stack canaries and control-flow integrity, typically impose a recurring cost on products and development teams, often putting security and other product requirements in conflict:

  • They come with performance overhead, impacting execution speed, battery life, tail latencies, and memory usage, sometimes preventing their deployment.
  • Attackers are seemingly infinitely creative, resulting in a cat-and-mouse game with defenders. In addition, the bar to develop and weaponize an exploit is regularly being lowered through better tooling and other advancements.

3rd generation: proactive vulnerability discovery. The following generation focused on detecting vulnerabilities. This includes sanitizers, often paired with fuzzing like libfuzzer, many of which were built by Google. While helpful, these methods address the symptoms of memory unsafety, not the root cause. They typically require constant pressure to get teams to fuzz, triage, and fix their findings, resulting in low coverage. Even when applied thoroughly, fuzzing does not provide high assurance, as evidenced by vulnerabilities found in extensively fuzzed code.

Products across the industry have been significantly strengthened by these approaches, and we remain committed to responding to, mitigating, and proactively hunting for vulnerabilities. Having said that, it has become increasingly clear that those approaches are not only insufficient for reaching an acceptable level of risk in the memory-safety domain, but incur ongoing and increasing costs to developers, users, businesses, and products. As highlighted by numerous government agencies, including CISA, in their secure-by-design report, "only by incorporating secure by design practices will we break the vicious cycle of constantly creating and applying fixes."

The fourth generation: high-assurance prevention

The shift towards memory safe languages represents more than just a change in technology, it is a fundamental shift in how to approach security. This shift is not an unprecedented one, but rather a significant expansion of a proven approach. An approach that has already demonstrated remarkable success in eliminating other vulnerability classes like XSS.

The foundation of this shift is Safe Coding, which enforces security invariants directly into the development platform through language features, static analysis, and API design. The result is a secure by design ecosystem providing continuous assurance at scale, safe from the risk of accidentally introducing vulnerabilities.

The shift from previous generations to Safe Coding can be seen in the quantifiability of the assertions that are made when developing code. Instead of focusing on the interventions applied (mitigations, fuzzing), or attempting to use past performance to predict future security, Safe Coding allows us to make strong assertions about the code's properties and what can or cannot happen based on those properties.

Safe Coding's scalability lies in its ability to reduce costs by:

  • Breaking the arms race: Instead of an endless arms race of defenders attempting to raise attackers’ costs by also raising their own, Safe Coding leverages our control of developer ecosystems to break this cycle by focusing on proactively building secure software from the start.
  • Commoditizing high assurance memory safety: Rather than precisely tailoring interventions to each asset's assessed risk, all while managing the cost and overhead of reassessing evolving risks and applying disparate interventions, Safe Coding establishes a high baseline of commoditized security, like memory-safe languages, that affordably reduces vulnerability density across the board. Modern memory-safe languages (especially Rust) extend these principles beyond memory safety to other bug classes.
  • Increasing productivity: Safe Coding improves code correctness and developer productivity by shifting bug finding further left, before the code is even checked in. We see this shift showing up in important metrics such as rollback rates (emergency code revert due to an unanticipated bug). The Android team has observed that the rollback rate of Rust changes is less than half that of C++.

From lessons to action

Interoperability is the new rewrite

Based on what we’ve learned, it's become clear that we do not need to throw away or rewrite all our existing memory-unsafe code. Instead, Android is focusing on making interoperability safe and convenient as a primary capability in our memory safety journey. Interoperability offers a practical and incremental approach to adopting memory safe languages, allowing organizations to leverage existing investments in code and systems, while accelerating the development of new features.

We recommend focusing investments on improving interoperability, as we are doing with

Rust ↔︎ C++ and Rust ↔︎ Kotlin. To that end, earlier this year, Google provided a $1,000,000 grant to the Rust Foundation, in addition to developing interoperability tooling like Crubit and autocxx.

Role of previous generations

As Safe Coding continues to drive down risk, what will be the role of mitigations and proactive detection? We don’t have definitive answers in Android, but expect something like the following:

  • More selective use of proactive mitigations: We expect less reliance on exploit mitigations as we transition to memory-safe code, leading to not only safer software, but also more efficient software. For instance, after removing the now unnecessary sandbox, Chromium's Rust QR code generator is 95% faster.
  • Decreased use, but increased effectiveness of proactive detection: We anticipate a decreased reliance on proactive detection approaches like fuzzing, but increased effectiveness, as achieving comprehensive coverage over small well-encapsulated code snippets becomes more feasible.

Final thoughts

Fighting against the math of vulnerability lifetimes has been a losing battle. Adopting Safe Coding in new code offers a paradigm shift, allowing us to leverage the inherent decay of vulnerabilities to our advantage, even in large existing systems. The concept is simple: once we turn off the tap of new vulnerabilities, they decrease exponentially, making all of our code safer, increasing the effectiveness of security design, and alleviating the scalability challenges associated with existing memory safety strategies such that they can be applied more effectively in a targeted manner.

This approach has proven successful in eliminating entire vulnerability classes and its effectiveness in tackling memory safety is increasingly evident based on more than half a decade of consistent results in Android.

We'll be sharing more about our secure-by-design efforts in the coming months.

Acknowledgements

Thanks Alice Ryhl for coding up the simulation. Thanks to Emilia Kasper, Adrian Taylor, Manish Goregaokar, Christoph Kern, and Lars Bergstrom for your helpful feedback on this post.

Notes

  1. Simulation was based on numbers similar to Android and other Google projects. The code base doubles every 6 years. The average lifetime for vulnerabilities is 2.5 years. It takes 10 years to transition to memory safe languages for new code, and we use a sigmoid function to represent the transition. Note that the use of the sigmoid function is why the second chart doesn’t initially appear to be exponential. ↩

  2. Alexopoulos et al. "How Long Do Vulnerabilities Live in the Code? A Large-Scale Empirical Measurement Study on FOSS Vulnerability Lifetimes". USENIX Security 22. ↩

  3. Unlike our simulation, these are vulnerabilities from a real code base, which comes with higher variance, as you can see in the slight increase in 2023. Vulnerability reports were unusually high that year, but in line with expectations given code growth, so while the percentage of memory safety vulnerabilities continued to drop, the absolute number increased slightly. ↩

Google & Arm – Raising The Bar on GPU Security

Posted by Xuan Xing, Eugene Rodionov, Jon Bottarini, Adam Bacchus - Android Red Team; Amit Chaudhary, Lyndon Fawcett, Joseph Artgole - Arm Product Security Team

Who cares about GPUs?

You, me, and the entire ecosystem! GPUs (graphics processing units) are critical in delivering rich visual experiences on mobile devices. However, the GPU software and firmware stack has become a way for attackers to gain permissions and entitlements (privilege escalation) to Android-based devices. There are plenty of issues in this category that can affect all major GPU brands, for example, CVE-2023-4295, CVE-2023-21106, CVE-2021-0884, and more. Most exploitable GPU vulnerabilities are in the implementation of the GPU kernel mode modules. These modules are pieces of code that load/unload during runtime, extending functionality without the need to reboot the device.

Proactive testing is good hygiene as it can lead to the detection and resolution of new vulnerabilities before they’re exploited. It’s also one of the most complex investigations to do as you don’t necessarily know where the vulnerability will appear (that’s the point!). By combining the expertise of Google’s engineers with IP owners and OEMs, we can ensure the Android ecosystem retains a strong measure of integrity.

Why investigate GPUs?

When researching vulnerabilities, GPUs are a popular target due to:

  1. Functionality vs. Security Tradeoffs

    Nobody wants a slow, unresponsive device; any hits to GPU performance could result in a noticeably degraded user experience. As such, the GPU software stack in Android relies on an in-process HAL model where the API & user space drivers communicating with the GPU kernel mode module are running directly within the context of apps, thus avoiding IPC (interprocess communication). This opens the door for potentially untrusted code from a third party app being able to directly access the interface exposed by the GPU kernel module. If there are any vulnerabilities in the module, the third party app has an avenue to exploit them. As a result, a potentially untrusted code running in the context of the third party application is able to directly access the interface exposed by the GPU kernel module and exploit potential vulnerabilities in the kernel module.

  2. Variety & Memory Safety

    Additionally, the implementation of GPU subsystems (and kernel modules specifically) from major OEMs are increasingly complex. Kernel modules for most GPUs are typically written in memory unsafe languages such as C, which are susceptible to memory corruption vulnerabilities like buffer overflow.

Can someone do something about this?

Great news, we already have! Who’s we? The Android Red Team and Arm! We’ve worked together to run an engagement on the Mali GPU (more on that below), but first, a brief introduction:

Android Red Team

The Android Red Team performs time-bound security assessment engagements on all aspects of the Android open source codebase and conducts regular security reviews and assessments of internal Android components. Throughout these engagements, the Android Red Team regularly collaborates with 3rd party software and hardware providers to analyze and understand proprietary and “closed source” code repositories and relevant source code that are utilized by Android products with the sole objective to identify security risks and potential vulnerabilities before they can be exploited by adversaries outside of Android. This year, the Android Red Team collaborated directly with our industry partner, Arm, to conduct the Mali GPU engagement and further secure millions of Android devices.

Arm Product Security and GPU Teams

Arm has a central product security team that sets the policy and practice across the company. They also have dedicated product security experts embedded in engineering teams. Arm operates a systematic approach which is designed to prevent, discover, and eliminate security vulnerabilities. This includes a Security Development Lifecycle (SDL), a Monitoring capability, and Incident Response. For this collaboration the Android Red Teams were supported by the embedded security experts based in Arm’s GPU engineering team.

Working together to secure Android devices

Google’s Android Security teams and Arm have been working together for a long time. Security requirements are never static, and challenges exist with all GPU vendors. By frequently sharing expertise, the Android Red Team and Arm were able to accelerate detection and resolution. Investigations of identified vulnerabilities, potential remediation strategies, and hardening measures drove detailed analyses and the implementation of fixes where relevant.

Recent research focused on the Mali GPU because it is the most popular GPU in today's Android devices. Collaborating on GPU security allowed us to:

  1. Assess the impact on the broadest segment of the Android Ecosystem: The Arm Mali GPU is one of the most used GPUs by original equipment manufacturers (OEMs) and is found in many popular mobile devices. By focusing on the Arm Mali GPU, the Android Red Team could assess the security of a GPU implementation running on millions of Android devices worldwide.
  2. Evaluate the reference implementation and vendor-specific changes: Phone manufacturers often modify the upstream implementation of GPUs. This tailors the GPU to the manufacturer's specific device(s). These modifications and enhancements are always challenging to make, and can sometimes introduce security vulnerabilities that are not present in the original version of the GPU upstream. In this specific instance, the Google Pixel team actively worked with the Android Red Team to better understand and secure the modifications they made for Pixel devices.

Improvements

Investigations have led to significant improvements, leveling up the security of the GPU software/firmware stack across a wide segment of the Android ecosystem.

Testing the kernel driver

One key component of the GPU subsystem is its kernel mode driver. During this engagement, both the Android Red Team and Arm invested significant effort looking at the Mali kbase kernel driver. Due to its complexity, fuzzing was chosen as the primary testing approach for this area. Fuzzing automates and scales vulnerability discovery in a way not possible via manual methods. With help from Arm, the Android Red Team added more syzkaller fuzzing descriptions to match the latest Mali kbase driver implementation.

The team built a few customizations to enable fuzzing the Mali kbase driver in the cloud, without physical hardware. This provided a huge improvement to fuzzing performance and scalability. With the Pixel team’s support, we also were able to set up fuzzing on actual Pixel devices. Through the combination of cloud-based fuzzing, Pixel-based fuzzing, and manual review, we were able to uncover two memory issues in Pixel’s customization of driver code (CVE-2023-48409 and CVE-2023-48421).

Both issues occurred inside of the gpu_pixel_handle_buffer_liveness_update_ioctl function, which is implemented by the Pixel team as part of device specific customization. These are both memory issues caused by integer overflow problems. If exploited carefully alongside other vulnerabilities, these issues could lead to kernel privilege escalation from user space. Both issues were fixed and the patch was released to affected devices in Pixel security bulletin 2023-12-01.

Testing the firmware

Firmware is another fundamental building block of the GPU subsystem. It’s the intermediary working with kernel drivers and GPU hardware. In many cases, firmware functionality is directly/indirectly accessible from the application. So “application ⇒ kernel ⇒ firmware ⇒ kernel” is a known attack flow in this area. Also, in general, firmware runs on embedded microcontrollers with limited resources. Commonly used security kernel mitigations (ASLR, stack protection, heap protection, certain sanitizers, etc.) might not be applicable to firmware due to resource constraints and performance impact. This can make compromising firmware easier, in some cases, than directly compromising kernel drivers from user space. To test the integrity of existing firmware, the Android Red Team and Arm worked together to perform both fuzzing and formal verification along with manual analysis. This multi-pronged approach led to the discovery of CVE-2024-0153, which had a patch released in the July 2024 Android Security Bulletin.

CVE-2024-0153 happens when GPU firmware handles certain instructions. When handling such instructions, the firmware copies register content into a buffer. There are size checks before the copy operation. However, under very specific conditions, an out-of-bounds write happens to the destination buffer, leading to a buffer overflow. When carefully manipulated, this overflow will overwrite some other important structures following the buffer, causing code execution inside of the GPU firmware.

The conditions necessary to reach and potentially exploit this issue are very complex as it requires a deep understanding of how instructions are executed. With collective expertise, the Android Red Team and Arm were able to verify the exploitation path and leverage the issue to gain limited control of GPU firmware. This eventually circled back to the kernel to obtain privilege escalation. Arm did an excellent job to respond quickly and remediate the issue. Altogether, this highlights the strength of collaboration between both teams to dive deeper.

Time to Patch

It’s known that attackers exploit GPU vulnerabilities in the wild, and time to patch is crucial to reduce risk of exploitation and protect users. As a result of this engagement, nine new Security Test suite (STS) tests were built to help partners automatically check their builds for missing Mali kbase patches. (Security Test Suite is software provided by Google to help partners automate the process of checking their builds for missing security patches.)

What’s Next?

The Arm Product Security Team is actively involved in security-focused industry communities and collaborates closely with its ecosystem partners. The engagement with the Android Red Team, for instance, provides valuable enablement that drives best practices and product excellence. Building on this collaborative approach, Arm is complementing its product security assurance capabilities with a bug bounty program. This investment will expand Arm’s efforts to identify potential vulnerabilities. For more information on Arm's product security initiatives, please visit this product security page.

The Android Red Team and Arm continue to work together to proactively raise the bar on GPU security. With thorough testing, rapid fixing, and updates to the security test suite, we’re improving the ecosystem for Android users. The Android Red Team looks forward to replicating this working relationship with other ecosystem partners to make devices more secure.