Google Security Blog

Fuzzing internships for Open Source Software

Google Security Blog - Fri, 10/09/2020 - 1:00pm
Posted by Abhishek Arya, Chrome Security team

Open source software is the foundation of many modern software products. Over the years, developers increasingly have relied on reusable open source components for their applications. It is paramount that these open source components are secure and reliable, as weaknesses impact those that build upon it.

Google cares deeply about the security of the open source ecosystem and recently launched the Open Source Security Foundation with other industry partners. Fuzzing is an automated testing technique to find bugs by feeding unexpected inputs to a target program. At Google, we leverage fuzzing at scale to find tens of thousands of security vulnerabilities and stability bugs. This summer, as part of Google’s OSS internship initiative, we hosted 50 interns to improve the state of fuzz testing in the open source ecosystem.

The fuzzing interns worked towards integrating new projects and improving existing ones in OSS-Fuzz, our continuous fuzzing service for the open source community (which has 350+ projects, 22,700 bugs, 89% fixed). Several widely used open source libraries including but not limited to nginx, postgresql, usrsctp, and openexr, now have continuous fuzzing coverage as a result of these efforts.

Another group of interns focused on improving the security of the Linux kernel. syzkaller, a kernel fuzzing tool from Google, has been instrumental in finding kernel vulnerabilities in various operating systems. The interns were tasked with improving the fuzzing coverage by adding new descriptions to syzkaller like ip tunnels, io_uring, and bpf_lsm for example, refining the interface description language, and advancing kernel fault injection capabilities.

Some interns chose to write fuzzers for Android and Chrome, which are open source projects that billions of internet users rely on. For Android, the interns contributed several new fuzzers for uncovered areas - network protocols such as pppd and dns, audio codecs like monoblend, g722, and android framework. On the Chrome side, interns improved existing blackbox fuzzers, particularly in the areas: DOM, IPC, media, extensions, and added new libprotobuf-based fuzzers for Mojo.

Our last set of interns researched quite a few under-explored areas of fuzzing, some of which were fuzzer benchmarking, ML based fuzzing, differential fuzzing, bazel rules for build simplification and made useful contributions.

Over the course of the internship, our interns have reported over 150 security vulnerabilities and 750 functional bugs. Given the overall success of these efforts, we plan to continue hosting fuzzing internships every year to help secure the open source ecosystem and teach incoming open source contributors about the importance of fuzzing. For more information on the Google internship program and other student opportunities, check out careers.google.com/students. We encourage you to apply.

Categories: Google Security Blog

Privacy-Preserving Smart Input with Gboard

Google Security Blog - Wed, 10/07/2020 - 1:00pm
Posted by Yang Lu, Software Engineer, Angana Ghosh, Group Product Manager, and Xu Liu, Director of Engineering, Gboard team

Google Keyboard (a.k.a Gboard) has a critical mission to provide frictionless input on Android to empower users to communicate accurately and express themselves effortlessly. In order to accomplish this mission, Gboard must also protect users' private and sensitive data. Nothing users type is sent to Google servers. We recently launched privacy-preserving input by further advancing the latest federated technologies. In Android 11, Gboard also launched the contextual input suggestion experience by integrating on-device smarts into the user's daily communication in a privacy-preserving way.

Before Android 11, input suggestions were surfaced to users in several different places. In Android 11, Gboard launched a consistent and coordinated approach to access contextual input suggestions. For the first time, we've brought Smart Replies to the keyboard suggestions - powered by system intelligence running entirely on device. The smart input suggestions are rendered with a transparent layer on top of Gboard’s suggestion strip. This structure maintains the trust boundaries between the Android platform and Gboard, meaning sensitive personal content cannot be not accessed by Gboard. The suggestions are only sent to the app after the user taps to accept them.

For instance, when a user receives the message “Have a virtual coffee at 5pm?” in Whatsapp, on-device system intelligence predicts smart text and emoji replies “Sounds great!” and “

Categories: Google Security Blog

New Password Protections (and more!) in Chrome

Google Security Blog - Tue, 10/06/2020 - 12:00pm
Posted by AbdelKarim Mardini, Senior Product Manager, Chrome Passwords are often the first line of defense for our digital lives. Today, we’re improving password security on both Android and iOS devices by telling you if the passwords you’ve asked Chrome to remember have been compromised, and if so, how to fix them.

To check whether you have any compromised passwords, Chrome sends a copy of your usernames and passwords to Google using a special form of encryption. This lets Google check them against lists of credentials known to be compromised, but Google cannot derive your username or password from this encrypted copy.

We notify you when you have compromised passwords on websites, but it can be time-consuming to go find the relevant form to change your password. To help, we’re adding support for ".well-known/change-password" URLs that let Chrome take users directly to the right “change password” form after they’ve been alerted that their password has been compromised.

Along with these improvements, Chrome is also bringing Safety Check to mobile. In our next release, we will launch Safety Check on iOS and Android, which includes checking for compromised passwords, telling you if Safe Browsing is enabled, and whether the version of Chrome you are running is updated with the latest security protections. You will also be able to use Chrome on iOS to autofill saved login details into other apps or browsers.

In Chrome 86 we’ll also be launching a number of additional features to improve user security, including:

Enhanced Safe Browsing for Android

Earlier this year, we launched Enhanced Safe Browsing for desktop, which gives Chrome users the option of more advanced security protections.

When you turn on Enhanced Safe Browsing, Chrome can proactively protect you against phishing, malware, and other dangerous sites by sharing real-time data with Google’s Safe Browsing service. Among our users who have enabled checking websites and downloads in real time, our predictive phishing protections see a roughly 20% drop in users typing their passwords into phishing sites.

Improvements to password filling on iOS

We recently launched Touch-to-fill for passwords on Android to prevent phishing attacks. To improve security on iOS too, we’re introducing a biometric authentication step before autofilling passwords. On iOS, you’ll now be able to authenticate using Face ID, Touch ID, or your phone passcode. Additionally, Chrome Password Manager allows you to autofill saved passwords into iOS apps or browsers if you enable Chrome autofill in Settings.
Mixed form warnings and download blocking

Secure HTTPS pages may sometimes still have non-secure features. Earlier this year, Chrome began securing and blocking what’s known as “mixed content”, when secure pages incorporate insecure content. But there are still other ways that HTTPS pages can create security risks for users, such as offering downloads over non-secure links, or using forms that don’t submit data securely.

To better protect users from these threats, Chrome 86 is introducing mixed form warnings on desktop and Android to alert and warn users before submitting a non-secure form that’s embedded in an HTTPS page.

Additionally, Chrome 86 will block or warn on some insecure downloads initiated by secure pages. Currently, this change affects commonly abused file types, but eventually secure pages will only be able to initiate secure downloads of any type. For more details, see Chrome’s plan to gradually block mixed downloads altogether

We encourage developers to update their forms and downloads to use secure connections for the safety and privacy of their users.

Categories: Google Security Blog

Announcing the launch of the Android Partner Vulnerability Initiative

Google Security Blog - Fri, 10/02/2020 - 1:01pm

Posted by Kylie McRoberts, Program Manager and Alec Guertin, Security Engineer

Google’s Android Security & Privacy team has launched the Android Partner Vulnerability Initiative (APVI) to manage security issues specific to Android OEMs. The APVI is designed to drive remediation and provide transparency to users about issues we have discovered at Google that affect device models shipped by Android partners.

Another layer of security

Android incorporates industry-leading security features and every day we work with developers and device implementers to keep the Android platform and ecosystem safe. As part of that effort, we have a range of existing programs to enable security researchers to report security issues they have found. For example, you can report vulnerabilities in Android code via the Android Security Rewards Program (ASR), and vulnerabilities in popular third-party Android apps through the Google Play Security Rewards Program. Google releases ASR reports in Android Open Source Project (AOSP) based code through the Android Security Bulletins (ASB). These reports are issues that could impact all Android based devices. All Android partners must adopt ASB changes in order to declare the current month’s Android security patch level (SPL). But until recently, we didn’t have a clear way to process Google-discovered security issues outside of AOSP code that are unique to a much smaller set of specific Android OEMs. The APVI aims to close this gap, adding another layer of security for this targeted set of Android OEMs.

Improving Android OEM device security

The APVI covers Google-discovered issues that could potentially affect the security posture of an Android device or its user and is aligned to ISO/IEC 29147:2018 Information technology -- Security techniques -- Vulnerability disclosure recommendations. The initiative covers a wide range of issues impacting device code that is not serviced or maintained by Google (these are handled by the Android Security Bulletins).

Protecting Android users

The APVI has already processed a number of security issues, improving user protection against permissions bypasses, execution of code in the kernel, credential leaks and generation of unencrypted backups. Below are a few examples of what we’ve found, the impact and OEM remediation efforts.

Permission Bypass

In some versions of a third-party pre-installed over-the-air (OTA) update solution, a custom system service in the Android framework exposed privileged APIs directly to the OTA app. The service ran as the system user and did not require any permissions to access, instead checking for knowledge of a hardcoded password. The operations available varied across versions, but always allowed access to sensitive APIs, such as silently installing/uninstalling APKs, enabling/disabling apps and granting app permissions. This service appeared in the code base for many device builds across many OEMs, however it wasn’t always registered or exposed to apps. We’ve worked with impacted OEMs to make them aware of this security issue and provided guidance on how to remove or disable the affected code.

Credential Leak

A popular web browser pre-installed on many devices included a built-in password manager for sites visited by the user. The interface for this feature was exposed to WebView through JavaScript loaded in the context of each web page. A malicious site could have accessed the full contents of the user’s credential store. The credentials are encrypted at rest, but used a weak algorithm (DES) and a known, hardcoded key. This issue was reported to the developer and updates for the app were issued to users.

Overly-Privileged Apps

The checkUidPermission method in the PackageManagerService class was modified in the framework code for some devices to allow special permissions access to some apps. In one version, the method granted apps with the shared user ID com.google.uid.shared any permission they requested and apps signed with the same key as the com.google.android.gsf package any permission in their manifest. Another version of the modification allowed apps matching a list of package names and signatures to pass runtime permission checks even if the permission was not in their manifest. These issues have been fixed by the OEMs. More information

Keep an eye out at https://bugs.chromium.org/p/apvi/ for future disclosures of Google-discovered security issues under this program, or find more information there on issues that have already been disclosed.

Acknowledgements: Scott Roberts, Shailesh Saini and Łukasz Siewierski, Android Security and Privacy Team

Categories: Google Security Blog