As Mobile World Congress approaches, we have the opportunity to have deep and meaningful conversations across the industry about the present and future of connected device security. Ahead of the event, we wanted to take a moment to recognize and share additional details on the notable progress being made to form harmonized connected device security standards and certification initiatives that provide users with better transparency about how their sensitive data is protected.
Supporting the GSMA Working Party for Mobile Device Security TransparencyWe’re pleased to support and participate in the recently announced GSMA working party, which will develop a first-of-its-kind smartphone security certification program. The program will leverage the Consumer Mobile Device Protection Profile (CMD PP) specification released by ETSI, a European Standards Development Organization (SDO), and will provide a consistent way to evaluate smartphones for critical capabilities like encryption, security updates, biometrics, networking, trusted hardware, and more.
This initiative should help address a significant gap in the market for consumers and policy makers, who will greatly benefit from a new, central security resource. Most importantly, these certification programs will evaluate connected devices across industry-accepted criteria. Widely-used devices, including smartphones and tablets, which currently do not have a familiar security benchmark or system in place, will be listed with key information on device protection capabilities to bring more transparency to users.
We hope this industry-run certification program can also benefit users and support policy makers in their work as they address baseline requirements and harmonization of standards.As policy makers consider changes through regulation and legislation, such as the UK’s Product Security and Telecommunications Infrastructure Act (PSTI), and emerging regulation like the EU Cyber Security and Cyber Resilience Acts, we share the concerns that today we are not equipped with globally recognized standards that are critical to increased security across the ecosystem. We join governments in the call to come together to ensure that we can build workable, harmonized standards to protect the security of users and mobile infrastructure today and build the resilience needed to protect our future.
The Importance of Harmonized Standards for Connected Devices
Connected devices, not just smartphones, are increasingly becoming the primary touchpoint for the most important aspects of our personal lives. From controlling the temperature of your home, to tracking your latest workout – connected devices have become embedded in our day-to-day tasks and activities. As consumers increasingly entrust more of their lives to their connected devices, they’re right to question the security protections provided and demand more transparency from manufacturers.
After we participated in a recent White House Workshop on IoT security labeling, we shared more about our commitment to security and transparency by announcing the extension of device security assessments – which started with Pixel 3 and now includes Nest, and Fitbit hardware. We have and always will strive to ensure our newly released products comply with the most prevalent security baselines that are defined by industry-recognized standards organizations. We will also remain transparent about critical security features – like how long our devices will receive security updates and our collaboration with security researchers that help us identify and fix security issues to help keep users safe.
By participating in international standards and certification programs such as our work as a member of the Connectivity Standards Alliance (Alliance), we’re working to raise the bar for the industry and develop a consistent set of security requirements that users can rely on.
New Research Continues to Help Inform Our Efforts to Establish Strong Security Standards and Labeling Practices
Last year, the Alliance formed the Product Security Working Group (PSWG). Over the past nine months, the working group has been making terrific progress on its mission to build an industry-run certification program for IoT devices that aligns with existing and future regulatory requirements to reduce fragmentation and promote harmonization.
Today, the Alliance in partnership with independent research firm Omdia, published a comprehensive research report that outlines all of the currently published and emerging global IoT security regulations and the standards baselines they map to. This critical research enables PSWG to hone its focus and efforts on harmonizing between ETSI EN 303 645 and NIST IR 8425, as these two baseline security standards were found to underpin the vast majority of the regulations outlined in the research report.
The other notable area of the report highlighted the need for transparent security labeling for connected devices, which has also become a very important industry initiative. A large majority (77%) of consumers surveyed indicated a device label that explains the privacy and security practices of the manufacturer would be important or very important to their purchasing decision. Transparent security labeling is critical in helping consumers understand which devices meet specific security standards and requirements during evaluation. We recently provided our principles for IoT security labeling and will continue to be a key contributor to efforts around providing users with transparent device security labels.
Creating Strong Connected Device Security Standards Together
It’s been inspiring to see all of the progress that the Connectivity Standards Alliance, GSMA and the industry at large has made on security standards and labeling initiatives in such a short time. It’s even more exciting to see how much collaboration there has been between both industry and the public sector on these efforts. We look forward to continuing the conversation and coordinating on these important security initiatives with policymakers, industry partners, developers and public interest advocates to bring more security and transparency to connected device users.
It has been another incredible year for the Vulnerability Reward Programs (VRPs) at Google! Working with security researchers throughout 2022, we have been able to identify and fix over 2,900 security issues and continue to make our products more secure for our users around the world.
We are thrilled to see significant year-over-year growth for our VRPs, and have had yet another record-breaking year for our programs! In 2022 we awarded over $12 million in bounty rewards – with researchers donating over $230,000 to a charity of their choice.
As in past years, we are sharing our 2022 Year in Review statistics across all of our programs. We would like to give a special thank you to all of our dedicated researchers for their continued work with our programs - we look forward to more collaboration in the future!
Android and Devices
The Android VRP had an incredible record breaking year in 2022 with $4.8 million in rewards and the highest paid report in Google VRP history of $605,000!
In our continued effort to ensure the security of Google device users, we have expanded the scope of Android and Google Devices in our program and are now incentivizing vulnerability research in the latest versions of Google Nest and Fitbit! For more information on the latest program version and qualifying vulnerability reports, please visit our public rules page.
We are also excited to share that the invite-only Android Chipset Security Reward Program (ACSRP) - a private vulnerability reward program offered by Google in collaboration with manufacturers of Android chipsets - rewarded $486,000 in 2022 and received over 700 valid security reports.
We would like to give a special shoutout to some of our top researchers, whose continued hard work helps to keep Android safe and secure:
Chrome
Chrome VRP had another unparalleled year, receiving 470 valid and unique security bug reports, resulting in a total of $4 million of VRP rewards. Of the $4M, $3.5 million was rewarded to researchers for 363 reports of security bugs in Chrome Browser and nearly $500,000 was rewarded for 110 reports of security bugs in ChromeOS.
This year, Chrome VRP re-evaluated and refactored the Chrome VRP reward amounts to increase the reward amounts for the most exploitable and harmful classes and types of security bugs, as well as added a new category for memory corruption bugs in highly privileged processes, such as the GPU and network process, to incentivize research in these critical areas. The Chrome VRP increased the fuzzer bonuses for reports from VRP-submitted fuzzers running on the Google ClusterFuzz infrastructure as part of the Chrome Fuzzing program. A new bisect bonus was introduced for bisections performed as part of the bug report submission, which helps the security team with our triage and bug reproduction.
2023 will be the year of experimentation in the Chrome VRP! Please keep a lookout for announcements of experiments and potential bonus opportunities for Chrome Browser and ChromeOS security bugs.
The entire Chrome team sincerely appreciates the contributions of all our researchers in 2022 who helped keep Chrome Browser, ChromeOS, and all the browsers and software based on Chromium secure for billions of users across the globe.
In addition to posting about our Top 0-22 Researchers in 2022, Chrome VRP would like to specifically acknowledge some specific researcher achievements made in 2022:
Securing Open Source
Recognizing the fact that Google is one of the largest contributors and users of open source in the world, in August 2022 we launched OSS VRP to reward vulnerabilities in Google's open source projects - covering supply chain issues of our packages, and vulnerabilities that may occur in end products using our OSS. Since then, over 100 bughunters have participated in the program and were rewarded over $110,000.
Sharing Knowledge
We’re pleased to announce that in 2022, we’ve made the learning opportunities for bug hunters available at our Bug Hunter University (BHU) more diverse and accessible. In addition to our existing collections of articles, which support improving your reports and avoiding invalid reports, we’ve made more than 20 instructional videos available. Clocking in at around 10 minutes each, these videos cover the most relevant learning topics and trends we’ve observed over the past years.
To make this happen, we teamed up with some of your favorite and best-known security researchers from around the globe, including LiveOverflow, PwnFunction, stacksmashing, InsiderPhD, PinkDraconian, and many more!
If you’re tired of reading our articles, or simply curious and looking for an alternative way to expand your bug hunting skills, these videos are for you. Check out our overview, or hop right in to the BHU YouTube playlist. Happy watching & learning!
Google Play
2022 was a year of change for the Google Play Security Reward Program. In May we onboarded both new teammates and some old friends to triage and lead GPSRP. We also sponsored NahamCon ‘22, BountyCon in Singapore, and NahamCon Europe’s online event. In 2023 we hope to continue to grow the program with new bug hunters and partner on more events focused on Android & Google Play apps.
Research Grants
In 2022 we continued our Vulnerability Research Grant program with success. We’ve awarded more than $250,000 in grants to over 170 security researchers. Last year we also piloted collaboration double VRP rewards for selected grants and are looking forward to expanding it even more in 2023.
If you are a Google VRP researcher and want to be considered for a Vulnerability Research Grant, make sure you opted in on your bughunters profile.
Looking Forward
Without our incredible security researchers we wouldn’t be here sharing this amazing news today. Thank you again for your continued hard work!
Also, in case you haven’t seen Hacking Google yet, make sure to check out the “Bug Hunters” episode, featuring some of our very own super talented bug hunters.
Thank you again for helping to make Google, the Internet, and our users more safe and secure! Follow us on @GoogleVRP for other news and updates.
Thank you to Adam Bacchus, Dirk Göhmann, Eduardo Vela, Sarah Jacobus, Amy Ressler, Martin Straka, Jan Keller, Tony Mendez, Rishika Hooda, Medha Jain
A modern Android powered smartphone is a complex hardware device: Android OS runs on a multi-core CPU - also called an Application Processor (AP). And the AP is one of many such processors of a System On Chip (SoC). Other processors on the SoC perform various specialized tasks — such as security functions, image & video processing, and most importantly cellular communications. The processor performing cellular communications is often referred to as the baseband. For the purposes of this blog, we refer to the software that runs on all these other processors as “Firmware”.
Securing the Android Platform requires going beyond the confines of the Application Processor (AP). Android’s defense-in-depth strategy also applies to the firmware running on bare-metal environments in these microcontrollers, as they are a critical part of the attack surface of a device.
As the security of the Android Platform has been steadily improved, some security researchers have shifted their focus towards other parts of the software stack, including firmware. Over the last decade there have been numerous publications, talks, Pwn2Own contest winners, and CVEs targeting exploitation of vulnerabilities in firmware running in these secondary processors. Bugs remotely exploitable over the air (eg. WiFi and cellular baseband bugs) are of particular concern and, therefore, are popular within the security research community. These types of bugs even have their own categorization in well known 3rd party exploit marketplaces.
Regardless of whether it is remote code execution within the WiFi SoC or within the cellular baseband, a common and resonating theme has been the consistent lack of exploit mitigations in firmware. Conveniently, Android has significant experience in enabling exploit mitigations across critical attack surfaces.
Over the last few years, we have successfully enabled compiler-based mitigations in Android — on the AP — which add additional layers of defense across the platform, making it harder to build reproducible exploits and to prevent certain types of bugs from becoming vulnerabilities. Building on top of these successes and lessons learned, we’re applying the same principles to hardening the security of firmware that runs outside of Android per se, directly on the bare-metal hardware.
In particular, we are working with our ecosystem partners in several areas aimed at hardening the security of firmware that interacts with Android:
Compiler-based sanitizers have no runtime requirements in trapping mode, which provides a meaningful layer of protection we want: it causes the program to abort execution when detecting undefined behavior. As a result, memory corruption vulnerabilities that would otherwise be exploitable are now stopped entirely. To aid developers in testing, troubleshooting, and generating bug reports on debug builds, both minimal and full diagnostics modes can be enabled, which require defining and linking the requisite runtime handlers.
Most Control Flow Integrity (CFI) schemes also work for bare-metal targets in trapping mode. LLVM’s1 CFI across shared libraries scheme (cross-DSO) is the exception as it requires a runtime to be defined for the target. Shadow Call Stack, an AArch64-only feature, has a runtime component which initializes the shadow stack. LLVM does not provide this runtime for any target, so bare-metal users would need to define that runtime to use it.
Enabling exploit mitigations in firmware running on bare metal targets is no easy feat. While the AP (Application Processor) hosts a powerful operating system (Linux) with comparatively abundant CPU and memory resources, bare metal targets are often severely resource-constrained, and are tuned to run a very specific set of functions. Any perturbation in compute and/or memory consumption introduced by enabling, for example, compiler-based sanitizers, could have a significant impact in functionality, performance, and stability.
Therefore, it is critical to optimize how and where exploit mitigations are turned on. The goal is to maximize impact — harden the most exposed attack surface — while minimizing any performance/stability impact. For example, in the case of the cellular baseband, we recommend focusing on code and libraries responsible for parsing messages delivered over the air (particularly for pre-authentication protocols such as RRC and NAS, which are the most exposed attack surface), libraries encoding/decoding complex formats (for example ASN.1), and libraries implementing IMS (IP Multimedia System) functionality, or parsing SMS and/or MMS.
Enabling exploit mitigations and compiler-based sanitizers are excellent techniques to minimize the chances of unknown bugs becoming exploitable. However, it is also important to continuously look for, find, and patch bugs.
Fuzzing continues to be a highly efficient method to find impactful bugs. It’s also been proven to be effective for signaling larger design issues in code. Our team partners closely with Android teams working on fuzzing and security assessments to leverage their expertise and tools with bare metal targets.
This collaboration also allowed us to scale fuzzing activities across Google by deploying central infrastructure that allows fuzzers to run in perpetuity. This is a high-value approach known as continuous fuzzing.
In parallel, we also accept and reward external contributions via our Vulnerability Rewards Program. Along with the launch of Android 13, we updated the severity guidelines to further highlight remotely exploitable bugs in connectivity firmware. We look forward to the contributions from the security research community to help us find and patch bugs in bare metal targets.
In Android 12 we announced support for Rust in the Android platform, and Android 13 is the first release with a majority of new code written in a memory safe language. We see a lot of potential in also leveraging memory-safe languages for bare metal targets, particularly for high risk and exposed attack surface.
Hardening firmware running on bare metal to materially increase the level of protection - across more surfaces in Android - is one of the priorities of Android Security. Moving forward, our goal is to expand the use of these mitigation technologies for more bare metal targets, and we strongly encourage our partners to do the same. We stand ready to assist our ecosystem partners to harden bare metal firmware.
Special thanks to our colleagues who contributed to this blog post and our firmware security hardening efforts: Diana Baker, Farzan Karimi, Jeffrey Vander Stoep, Kevin Deus, Eugene Rodionov, Pirama Arumuga Nainar, Sami Tolvanen, Stephen Hines, Xuan Xing, Yomna Nasser.
LLVM - is a compiler framework used by multiple programming languages ↩
Should companies be responsible for cyberattacks? The U.S. government thinks so – and frankly, we agree.
Jen Easterly and Eric Goldstein of the Cybersecurity and Infrastructure Security Agency at the Department of Homeland Security planted a flag in the sand:
“The incentives for developing and selling technology have eclipsed customer safety in importance. […] Americans…have unwittingly come to accept that it is normal for new software and devices to be indefensible by design. They accept products that are released to market with dozens, hundreds, or even thousands of defects. They accept that the cybersecurity burden falls disproportionately on consumers and small organizations, which are often least aware of the threat and least capable of protecting themselves.”
We think they’re right. It’s time for companies to step up on their own and work with governments to help fix a flawed ecosystem. Just look at the growing threat of ransomware, where bad actors lock up organizations’ systems and demand payment or ransom to restore access. Ransomware affects every industry, in every corner of the globe – and it thrives on pre-existing vulnerabilities: insecure software, indefensible architectures, and inadequate security investment.
Remember that sophisticated ransomware operators have bosses and budgets too. They increase their return on investment by exploiting outdated and insecure technology systems that are too hard to defend. Alarmingly, the most significant source of compromise is through exploitation of known vulnerabilities, holes sometimes left unpatched for years. While law enforcement works to bring ransomware operators to justice, this merely treats the symptoms of the problem.
Treating the root causes will require addressing the underlying sources of digital vulnerabilities. As Easterly and Goldstein rightly point out, “secure by default” and “secure by design” should be table stakes.
The bottom line: People deserve products that are secure by default and systems that are built to withstand the growing onslaught from attackers. Safety should be fundamental: built-in, enabled out of the box, and not added on as an afterthought. In other words, we need secure products, not security products. That’s why Google has worked to build security in – often making it invisible – to our users. Many of our most significant security features, including innovations like SafeBrowsing, do their best work behind the scenes for our core consumer products.
There’s come to be an unfortunate belief that security features are cumbersome and hurt user experience. That can be true – but it doesn’t need to be. We can make the safe path the easiest, most helpful path for people using our products. Our approach to multi-factor authentication – one of the most important controls to defend against phishing attacks – provides a great example. Since 2021, we’ve turned on 2-Step Verification (2SV) by default for hundreds of millions of people to add an additional layer of security across their online accounts. If we had simply announced 2SV as an available option for people to enroll in, it would have failed like so many other security add-ons. Instead, we pioneered an approach using in-app notifications that was so seamless and integrated, many of the millions of people we auto-enrolled never noticed they adopted 2SV. We’ve taken this approach even further by building the “second factor” right into phones – giving people the strongest form of account security as soon as they have their device.
As for secure by design: We all have to shift our focus from reactive incident response to upstream software development. That will demand a completely new approach to how companies build products and services. We’ve learned a lot in the past decade about reengineering security architectures, and actively apply those learnings to keep people safe online every day. Ensuring technology is secure by design should be like balancing budgets — a part of business as usual. However, it isn’t easy to cut-and-paste solutions here: developers need to think deeply about the threats their products will face, and design them from the ground up to withstand those attacks. And the same principles are true for securing the development process as they are for users: the secure engineering choice must also be the easiest and most helpful one.
Building security into every stage of the software development process takes work, but recent innovations, like our SLSA framework for secure software supply chains, and new general purpose memory-safe languages, are making it easier. Perhaps most significantly, adopting modern cloud architectures makes it easier to define and enforce secure software development policies.
Persistent collaboration between private and public sector partners is essential. No company can solve the cybersecurity challenge on its own. It’s a collective action problem that demands a collective solution, including international coordination and collaboration. Many public and private initiatives — threat sharing, incident response, law enforcement cooperation — are valuable, but address only symptoms, not root causes. We can do better than just holding attackers to account after the fact.
As Easterly and Goldstein write, “Americans need a new model, one they can trust to ensure the safety and integrity of the technology that they use every hour of every day.” Again, we agree, but in this case we’d take it a step further. Building this model and ensuring it can scale calls for close cooperation between tech companies, standards bodies, and government agencies. But since technologies and companies cross borders, we also need to take a global view: Cybersecurity is a team sport, and international coordination is essential to avoid conflicting requirements that unintentionally make it harder to secure software. Broad regulatory cooperation on cybersecurity will promote secure-by-default principles for everyone. This approach holds enormous promise, and not just for technologically advanced nations. Raising the security benchmark for basic consumer and enterprise technologies that all nations rely on offers far more bang for the buck. A far wider range of countries and companies can take these simple steps than can employ advanced cyber initiatives like detailed threat sharing and close operational collaboration. Given the interdependent nature of the ecosystem, we are only as strong as our weakest link. That means raising cyber standards globally will improve American resilience as well.
Of course, raising the security baseline won’t stop all bad actors, and software will likely always have flaws – but we can start by covering the basics, fixing the most egregious security risks, and coming up with new approaches that eliminate entire classes of threats. Google has made investments in the past two decades, but contributing resources is just a piece of the puzzle. It's work for all of us, but it's the responsible thing to do: The safety and security of our increasingly digitized world depends on it.
Since launching in 2016, Google's free OSS-Fuzz code testing service has helped get over 8800 vulnerabilities and 28,000 bugs fixed across 850 projects. Today, we’re happy to announce an expansion of our OSS-Fuzz Rewards Program, plus new features in OSS-Fuzz and our involvement in supporting academic fuzzing research.
The OSS-Fuzz project's purpose is to support the open source community in adopting fuzz testing, or fuzzing — an automated code testing technique for uncovering bugs in software. In addition to the OSS-Fuzz service, which provides a free platform for continuous fuzzing to critical open source projects, we established an OSS-Fuzz Reward Program in 2017 as part of our wider Patch Rewards Program.
We’ve operated this successfully for the past 5 years, and to date, the OSS-Fuzz Reward Program has awarded over $600,000 to over 65 different contributors for their help integrating new projects into OSS-Fuzz.
Today, we’re excited to announce that we’ve expanded the scope of the OSS-Fuzz Reward Program considerably, introducing many new types of rewards!
These new reward types cover contributions such as:
These changes boost the total rewards possible per project integration from a maximum of $20,000 to $30,000 (depending on the criticality of the project). In addition, we’ve also established two new reward categories that reward wider improvements across all OSS-Fuzz projects, with up to $11,337 available per category.
For more details, see the fully updated rules for our dedicated OSS-Fuzz Reward Program.
We’ve continuously made improvements to OSS-Fuzz’s infrastructure over the years and expanded our language offerings to cover C/C++, Go, Rust, Java, Python, and Swift, and have introduced support for new frameworks such as FuzzTest. Additionally, as part of an ongoing collaboration with Code Intelligence, we’ll soon have support for JavaScript fuzzing through Jazzer.js.
Last year, we launched the OpenSSF FuzzIntrospector tool and integrated it into OSS-Fuzz.
We’ve continued to build on this by adding new language support and better analysis, and now C/C++, Python, and Java projects integrated into OSS-Fuzz have detailed insights on how the coverage and fuzzing effectiveness for a project can be improved.
The FuzzIntrospector tool provides these insights by identifying complex code blocks that are blocked during fuzzing at runtime, as well as suggesting new fuzz targets that can be added. We’ve seen users successfully use this tool to improve the coverage of jsonnet, file, xpdf and bzip2, among others.
Anyone can use this tool to increase the coverage of a project and in turn be rewarded as part of the refreshed OSS-Fuzz rewards. See the full list of all OSS-Fuzz FuzzIntrospector reports to get started.
The OSS-Fuzz team maintains FuzzBench, a service that enables security researchers in academia to test fuzzing improvements against real-world open source projects. Approaching its third anniversary in serving free benchmarking, FuzzBench is cited by over 100 papers and has been used as a platform for academic fuzzing workshops such as NDSS’22.
This year, FuzzBench has been invited to participate in the SBFT'23 workshop in ICSE, a premier research conference in the field, which for the first time is hosting a fuzzing competition. During this competition, the FuzzBench platform will be used to evaluate state-of-the-art fuzzers submitted by researchers from around the globe on both code coverage and bug-finding metrics.
We believe these initiatives will help scale security testing efforts across the broader open source ecosystem. We hope to accelerate the integration of critical open source projects into OSS-Fuzz by providing stronger incentives to security researchers and open source maintainers. Combined with our involvement in fuzzing research, these efforts are making OSS-Fuzz an even more powerful tool, enabling users to find more bugs, and, more critically, find them before the bad guys do!
Note: This post is a follow-up to discussions carried out on the Mozilla “Dev Security Policy” Web PKI public discussion forum Google Group in December 2022. Google Chrome communicated its distrust of TrustCor in the public forum on December 15, 2022.
The Chrome Security Team prioritizes the security and privacy of Chrome’s users, and we are unwilling to compromise on these values.
Google includes or removes CA certificates within the Chrome Root Store as it deems appropriate for user safety in accordance with our policies. The selection and ongoing inclusion of CA certificates is done to enhance the security of Chrome and promote interoperability.
Behavior that attempts to degrade or subvert security and privacy on the web is incompatible with organizations whose CA certificates are included in the Chrome Root Store. Due to a loss of confidence in its ability to uphold these fundamental principles and to protect and safeguard Chrome’s users, certificates issued by TrustCor Systems will no longer be recognized as trusted by:
This change was first communicated in the Mozilla “Dev Security Policy” Web PKI public discussion forum Google Group on December 15, 2022.
This change will be implemented via our existing mechanisms to respond to CA incidents via:
Beginning approximately March 7, 2023, navigations to websites that use a certificate that chains to one of the roots detailed below will be considered insecure and result in a full page certificate error interstitial.
Affected Certificates (SHA-256 fingerprint):
This change will be integrated into the Chromium open-source project as part of a default build. Questions about the expected behavior in specific Chromium-based browsers should be directed to their maintainers.
This change will be incorporated as part of the regular Chrome release process to ensure sufficient time for testing and replacing affected certificates by website operators. Information about release timetables and milestones is available at https://chromiumdash.appspot.com/schedule.
Beginning approximately February 9, 2023, website operators can preview these changes in Chrome 111 Beta. Website operators will also be able to preview the change sooner, using our Dev and Canary channels. The majority of users will not encounter behavior changes until the release of Chrome 111 to the Stable channel, approximately March 7, 2023.
Summarizing security response of other Google products:
We are pleased to announce that moving forward, the Chromium project is going to support the use of third-party Rust libraries from C++ in Chromium. To do so, we are now actively pursuing adding a production Rust toolchain to our build system. This will enable us to include Rust code in the Chrome binary within the next year. We’re starting slow and setting clear expectations on what libraries we will consider once we’re ready.
In this blog post, we will discuss how we arrived at the decision to support third-party Rust libraries at this time, and not broader usage of Rust in Chromium.
Why We Chose to Bring Rust into Chromium
Our goal in bringing Rust into Chromium is to provide a simpler (no IPC) and safer (less complex C++ overall, no memory safety bugs in a sandbox either) way to satisfy the rule of two, in order to speed up development (less code to write, less design docs, less security review) and improve the security (increasing the number of lines of code without memory safety bugs, decreasing the bug density of code) of Chrome. And we believe that we can use third-party Rust libraries to work toward this goal.
Rust was developed by Mozilla specifically for use in writing a browser, so it’s very fitting that Chromium would finally begin to rely on this technology too. Thank you Mozilla for your huge contribution to the systems software industry. Rust has been an incredible proof that we should be able to expect a language to provide safety while also being performant.
We know that C++ and Rust can play together nicely, through tools like cxx, autocxx bindgen, cbindgen, diplomat, and (experimental) crubit. However there are also limitations. We can expect that the shape of these limitations will change in time through new or improved tools, but the decisions and descriptions here are based on the current state of technology.
How Chromium Will Support the Use of Rust
The Chrome Security team has been investing time into researching how we should approach using Rust alongside our C++ code. Understanding the implications of incrementally moving to writing Rust instead of C++, even in the middle of our software stack. What the limits of safe, simple, and reliable interop might be.
Based on our research, we landed on two outcomes for Chromium.
The Interop Between Rust and C++ in Chromium
We have observed that most successful C/C++ and Rust interop stories to date have been built around interop through narrow APIs (e.g. libraries for QUIC or bluetooth, Linux drivers) or through clearly isolated components (e.g. IDLs, IPCs). Chrome is built on foundational but really wide C++ APIs, such as the //content/public layer. We examined what it would mean for us to build Rust components against these types of APIs. At a high level what we found was that because C++ and Rust play by different rules, things can go sideways very easily.
For example, Rust guarantees temporal memory safety with static analysis that relies on two inputs: lifetimes (inferred or explicitly written) and exclusive mutability. The latter is incompatible with how the majority of Chromium’s C++ is written. We hold redundant mutable pointers throughout the system, and pointers that provide multiple paths to reach mutable pointers. We have cyclical mutable data structures. This is especially true in our browser process, which contains a giant interconnected system of (mutable) pointers. If these C++ pointers were also used as Rust references in a complex or long-lived way, it would require our C++ authors to understand the aliasing rules of Rust and prevent the possibility of violating them, such as by:
Without interop tools providing support via the compiler and the type system, developers would need to understand all of the assumptions being made by Rust compiler, in order to not violate them from C++. In this framing, C++ is much like unsafe Rust. And while unsafe Rust is very costly to a project, its cost is managed by keeping it encapsulated and to the minimum possible. In the same way, the full complexity of C++ would need to be encapsulated from safe Rust. Narrow APIs designed for interop can provide similar encapsulation, and we hope that interop tools can provide encapsulation in other ways that allow wider APIs between the languages.
The high-level summary is that without additional interop tooling support:
Any cross-language interop between arbitrary code introduces difficulties where concepts in one language are not found in the other. For Rust calling into C++, support for language features like templates or inheritance can be difficult for a binding generator to support. For C++ calling into Rust, proc macros, and traits are examples that provide similar challenges. At times, the impedance mismatch represents intentional design choices made for either language, however they also imply limits on FFI (interop) between the languages. We rely on interop tools to model the ideas of each language in a way that makes sense to the other, or to disallow them.
Accessing the Rust Ecosystem from Chromium
These challenges present an opportunity, both to make interop easier and more seamless, but also to get access to a wider range of libraries from either language. Google is investing in Crubit, an experiment in how to increase the fidelity of interop between C++ and Rust and express or encapsulate the requirements of each language to the other.
The Rust ecosystem is incredibly important, especially to a security-focused open source project like Chromium. The ecosystem is enormous (96k+ crates on crates.io) and growing, with investment from the systems development industry at large, including Google. Chrome relies heavily on third-party code, and we need to keep up with where that third-party investment is happening. It is critical that we build out support for including Rust into the Chromium project.
We will be following this strategy to establish norms, and to maintain a level of API review through the third-party process, while we look to the future of interop support pushing the boundaries of what is possible and reasonable to do between Rust and C++.
Some Other Related Content
Memory unsafety is an industry-wide problem, and making use of Rust is one part of a strategy to move the needle in this area. Recently, Android and Apple have each published a great blog post on the subject if you’re interested in learning more. With Chrome’s millions of lines of C++, we’re still working hard to improve the safety of our C++ too, through projects such as MiraclePtr.
The App Defense Alliance launched in 2019 with a mission to protect Android users from bad apps through shared intelligence and coordinated detection between alliance partners. Earlier this year, the App Defense Alliance expanded to include new initiatives outside of malware detection and is now the home for several industry-led collaborations including Malware Mitigation, MASA (Mobile App Security Assessment) & CASA (Cloud App Security Assessment). With a new dedicated landing page at appdefensealliance.dev, the ADA has an expanded mission to protect Android users by removing threats while improving app quality across the ecosystem. Let’s walk through some of the latest program updates from the past year, including the addition of new ADA members.
Malware Mitigation
Together, with the founding ADA members - Google, ESET, Lookout, and Zimperium, the alliance has been able to reduce the risk of app-based malware and better protect Android users. These partners have access to mobile apps as they are being submitted to the Google Play Store and scan thousands of apps daily, acting as another, vital set of eyes prior to an app going live on Play. Knowledge sharing and industry collaboration are important aspects in securing the world from attacks and that’s why we’re continuing to invest in the program.
New ADA Members
We’re excited to see the ADA expand with the additions of McAfee and Trend Micro. Both McAfee and Trend Micro are leaders in the antivirus space and we look forward to their contributions to the program.
Mobile App Security Assessment (MASA)
With consumers spending four to five hours per day in mobile apps, ensuring the safety of these services is more important than ever. According to Data.ai, the pandemic accelerated existing mobile habits - with app categories like finance growing 25% YoY and users spending over 100 billion hours in shopping apps.
That’s why the ADA introduced MASA (Mobile App Security Assessment), which allows developers to have their apps independently validated against the Mobile Application Security Verification Standard (MASVS standard) under the OWASP Mobile Application Security project. The project’s mission is to “Define the industry standard for mobile application security,” and has been used by both public and private sector organizations as a form of industry best practices when it comes to mobile application security. Developers can work directly with an ADA Authorized Lab to have their apps evaluated against a set of MASVS L1 requirements. Once successful, the app’s validation is listed in the recently launched App Validation Directory, which provides users a single place to view all app validations. The Directory also allows users to access more assessment details including validation date, test lab, and a report showing all test steps and requirements. The Directory will be updated over time with new features and search functionality to make it more user friendly.
The Google Play Store is the first commercial app store to recognize and display a badge for any app that has completed an independent security review through ADA MASA. The badge is displayed within an app’s respective Data Safety section.
To learn more about the program and to help developers get started, there’s a Play Academy course dedicated to independent security review. Check out the interactive guidance on the Academy for App Success and get started today!
Cloud App Security Assessment (CASA)
As the industry continues to evolve and software connects more systems through complex cloud-to-cloud integrations, focusing on the security of cloud applications and their supporting infrastructure becomes increasingly critical. CASA (Cloud App Security Assessment) leverages the work set forth in OWASP’s Application Security Verification Standard ASVS to provide a consistent set of requirements to harden security for any application. The CASA framework provides multiple assurance levels in which low-risk cloud applications can be evaluated using either a self assessment or automated scan. For applications which present higher risk (such as a large user base, recent security breach, or processes highly sensitive data), an Authorized Lab may perform an assessment.
Further, the CASA accelerator provides developers with a workflow that minimizes the required checks depending on the developer's current valid certifications. The CASA checks have been mapped to 10 certifications and frameworks which eliminate redundant testing while lowering the cost of the assessment. Google is continuing to invest in this space with plans to use ASVS more proactively with the developer community next year.
It's been amazing to see the ADA grow this year and we are excited for the continued progress and expansion around the alliance’s mission.
Today, we’re launching the OSV-Scanner, a free tool that gives open source developers easy access to vulnerability information relevant to their project.
Last year, we undertook an effort to improve vulnerability triage for developers and consumers of open source software. This involved publishing the Open Source Vulnerability (OSV) schema and launching the OSV.dev service, the first distributed open source vulnerability database. OSV allows all the different open source ecosystems and vulnerability databases to publish and consume information in one simple, precise, and machine readable format.
The OSV-Scanner is the next step in this effort, providing an officially supported frontend to the OSV database that connects a project’s list of dependencies with the vulnerabilities that affect them.
Software projects are commonly built on top of a mountain of dependencies—external software libraries you incorporate into a project to add functionalities without developing them from scratch. Each dependency potentially contains existing known vulnerabilities or new vulnerabilities that could be discovered at any time. There are simply too many dependencies and versions to keep track of manually, so automation is required.
Scanners provide this automated capability by matching your code and dependencies against lists of known vulnerabilities and notifying you if patches or updates are needed. Scanners bring incredible benefits to project security, which is why the 2021 U.S. Executive Order for Cybersecurity included this type of automation as a requirement for national standards on secure software development.
The OSV-Scanner generates reliable, high-quality vulnerability information that closes the gap between a developer’s list of packages and the information in vulnerability databases. Since the OSV.dev database is open source and distributed, it has several benefits in comparison with closed source advisory databases and scanners:
Running OSV-Scanner on your project will first find all the transitive dependencies that are being used by analyzing manifests, SBOMs, and commit hashes. The scanner then connects this information with the OSV database and displays the vulnerabilities relevant to your project.
OSV-Scanner is also integrated into the OpenSSF Scorecard’s Vulnerabilities check, which will extend the analysis from a project’s direct vulnerabilities to also include vulnerabilities in all its dependencies. This means that the 1.2M projects regularly evaluated by Scorecard will have a more comprehensive measure of their project security.
The OSV project has made lots of progress since our last post in June last year. The OSV schema has seen significant adoption from vulnerability databases such as GitHub Security Advisories and Android Security Bulletins. Altogether OSV.dev now supports 16 ecosystems, including all major language ecosystems, Linux distributions (Debian and Alpine), as well as Android, Linux Kernel, and OSS-Fuzz. This means the OSV.dev database is now the biggest open source vulnerability database of its kind, with a total of over 38,000 advisories from 15,000 advisories a year ago.
The OSV.dev website also had a complete overhaul, and now has a better UI and provides more information on each vulnerability. Prominent open source projects have also started to rely on OSV.dev, such as DependencyTrack and Flutter.
There’s still a lot to do! Our plan for OSV-Scanner is not just to build a simple vulnerability scanner; we want to build the best vulnerability management tool—something that will also minimize the burden of remediating known vulnerabilities. Here are some of our ideas for achieving this:
You can download and try out OSV-Scanner on your projects by following instructions on our new website osv.dev. Or alternatively, to automatically run OSV-Scanner on your GitHub project, try Scorecard. Please feel free to let us know what you think! You can give us feedback either by opening an issue on our Github, or through the OSV mailing list.