Google Security Blog

A new chapter for Google’s Vulnerability Reward Program

Google Security Blog - Tue, 07/27/2021 - 9:18am

Posted by Jan Keller, Technical Program Manager, Google VRP 
A little over 10 years ago, we launched our Vulnerability Rewards Program (VRP). Our goal was to establish a channel for security researchers to report bugs to Google and offer an efficient way for us to thank them for helping make Google, our users, and the Internet a safer place. To recap our progress on these goals, here is a snapshot of what VRP has accomplished with the community over the past 10 years:
  • Total bugs rewarded: 11,055
  • Number of rewarded researchers: 2,022
  • Representing 84 different countries
  • Total rewards: $29,357,516
To celebrate our anniversary and ensure the next 10 years are just as (or even more) successful and collaborative, we are excited to announce the launch of our new platform, bughunters.google.com.

This new site brings all of our VRPs (Google, Android, Abuse, Chrome and Play) closer together and provides a single intake form that makes it easier for bug hunters to submit issues. Other improvements you will notice include:
  • More opportunities for interaction and a bit of healthy competition through gamification, per-country leaderboards, awards/badges for certain bugs and more!
  • A more functional and aesthetically pleasing leaderboard. We know a lot of you are using your achievements in the VRP to find jobs (we’re hiring!) and we hope this acts as a useful resource.
  • A stronger emphasis on learning: Bug hunters can improve their skills through the content available in our new Bug Hunter University
  • Streamlined publication process: we know the value that knowledge sharing brings to our community. That’s why we want to make it easier for you to publish your bug reports.
  • Swag will now be supported for special occasions (we heard you loud and clear!)

We also want to take a moment to shine a light on some aspects of the VRP that are not yet well-known, such as:


When we launched our very first VRP, we had no idea how many valid vulnerabilities - if any - would be submitted on the first day. Everyone on the team put in their estimate, with predictions ranging from zero to 20. In the end, we actually received more than 25 reports, taking all of us by surprise.

Since its inception, the VRP program has not only grown significantly in terms of report volume, but the team of security engineers behind it has also expanded – including almost 20 bug hunters who reported vulnerabilities to us and ended up joining the Google VRP team.

That is why we are thrilled to bring you this new platform, continue to grow our community of bug hunters and support the skill development of up-and-coming vulnerability researchers.

Thanks again to the entire Google bug hunter community for making our vulnerability rewards program successful. As you continue to play around with the new site and reporting system, tell us about it - we would love to hear your feedback. Until next time, keep on finding those bugs!
Categories: Google Security Blog

Protecting more with Site Isolation

Google Security Blog - Tue, 07/20/2021 - 1:00pm
Posted by Charlie Reis​ and Alex Moshchuk, Chrome Security Team

Chrome's Site Isolation is an essential security defense that makes it harder for malicious web sites to steal data from other web sites. On Windows, Mac, Linux, and Chrome OS, Site Isolation protects all web sites from each other, and also ensures they do not share processes with extensions, which are more highly privileged than web sites. As of Chrome 92, we will start extending this capability so that extensions can no longer share processes with each other. This provides an extra line of defense against malicious extensions, without removing any existing extension capabilities.

Meanwhile, Site Isolation on Android currently focuses on protecting only high-value sites, to keep performance overheads low. Today, we are announcing two Site Isolation improvements that will protect more sites for our Android users. Starting in Chrome 92, Site Isolation will apply to sites where users log in via third-party providers, as well as sites that carry Cross-Origin-Opener-Policy headers.

Our ongoing goal with Site Isolation for Android is to offer additional layers of security without adversely affecting the user experience for resource-constrained devices. Site Isolation for all sites continues to be too costly for most Android devices, so our strategy is to improve heuristics for prioritizing sites that benefit most from added protection. So far, Chrome has been isolating sites where users log in by entering a password. However, many sites allow users to authenticate on a third-party site (for example, sites that offer "Sign in with Google"), possibly without the user ever typing in a password. This is most commonly accomplished with the industry-standard OAuth protocol. Starting in Chrome 92, Site Isolation will recognize common OAuth interactions and protect sites relying on OAuth-based login, so that user data is safe however a user chooses to authenticate.

Additionally, Chrome will now trigger Site Isolation based on the new Cross-Origin-Opener-Policy (COOP) response header. Supported since Chrome 83, this header allows operators of security-conscious websites to request a new browsing context group for certain HTML documents. This allows the document to better isolate itself from untrustworthy origins, by preventing attackers from referencing or manipulating the site's top-level window. It’s also one of the headers required to use powerful APIs such as SharedArrayBuffers. Starting in Chrome 92, Site Isolation will treat non-default values of the COOP header on any document as a signal that the document's underlying site may have sensitive data and will start isolating such sites. Thus, site operators who wish to ensure their sites are protected by Site Isolation on Android can do so by serving COOP headers on their sites.

As before, Chrome stores newly isolated sites locally on the device and clears the list whenever users clear their browsing history or other site data. Additionally, Chrome places certain restrictions on sites isolated by COOP to keep the list focused on recently-used sites, prevent it from growing overly large, and protect it from misuse (e.g., by requiring user interaction on COOP sites before adding them to the list). We continue to require a minimum RAM threshold (currently 2GB) for these new Site Isolation modes. With these considerations in place, our data suggests that the new Site Isolation improvements do not noticeably impact Chrome's overall memory usage or performance, while protecting many additional sites with sensitive user data.

Given these improvements in Site Isolation on Android, we have also decided to disable V8 runtime mitigations for Spectre on Android. These mitigations are less effective than Site Isolation and impose a performance cost. Disabling them brings Android on par with desktop platforms, where they have been turned off since Chrome 70. We advise that sites wanting to protect data from Spectre should consider serving COOP headers, which will in turn trigger Site Isolation.

Users who desire the most complete protection for their Android devices may manually opt in to full Site Isolation via chrome://flags/#enable-site-per-process, which will isolate all websites but carry higher memory cost.

Categories: Google Security Blog

Advancing an inclusive, diverse security industry

Google Security Blog - Tue, 07/20/2021 - 12:20pm


Posted by Sarah Morales, Community Outreach Manager, Security 

It’s no secret that lack of diversity in corporate America is a well-documented problem and improvements have been slow. To help improve female representation in the cybersecurity industry, Google teamed up with Women in Cybersecurity (WiCyS) and SANS Institute a year ago to establish the Security Training Scholarship Program.

The multi-stage security training program set participants on a path to launch and advance their careers in cybersecurity through skills development, introducing them to fundamental cybersecurity concepts with interactive challenges like Capture the Flag (CTF) and the SANS CyberStart Game, which introduces topics such as Linux, web attacks, programming, forensics, and more. Mentors and peers guide the participants through each stage of the program and top qualifiers then graduate and receive access to the SANS foundational security training courses, which readies and prepares these women for their first roles in the security industry. The goal is to get them employed in cybersecurity within the next 1.5 years and to create a powerful network of women in the field – in essence, drawing more women to the industry and helping to close the talent gap.


As the inaugural program comes to an end, we are proud to report that its overall impact includes:


  • 112 people received training-based scholarship
  • 15 Full Scholarship Recipients received the full course training, which includes:
    • CyberStart Game and SANS BootUp CTF
    • SANS SEC275 Foundations & Exam
    • SANS 401 Security Essentials Bootcamp and GSEC
    • Elective - SANS SEC504/GCIH, SEC488/GCLD, SEC560/GPEN, or SEC548/GWAPT
  • 24 certifications earned to date with 100% pass rate, with average score on GSEC 90%
  • Since 2013, only 2 people have scored 99% on GIAC Certified Incident Handler (GCIH) one is a WiCyS Scholarship Recipient
  • 1/3 of students were employed in direct information security roles before the program ended
  • 100% of Full Scholarship Recipients intend to have long term careers in information security (15+ years)
Participants praise the program’s strong networking component where they can support one another, share best practices, ask questions from SANS security experts and receive industry insight from members across Google’s security team. As Lynn Dohm, executive director of WiCyS, told us, “You cannot put a price tag on the power of community, and last year’s WiCyS Security Training Program proved just that.”

Here at Google, we are inspired by the dedication and passion the scholarship recipients have shown throughout the program and are eager to see what they accomplish throughout their careers.

Elizabeth Beattie, who was part of the inaugural program told us, “I learned that, as part of my scholarship program with WiCyS, SANS Institute and Google, I’ve been awarded a scholarship to attend the WiCyS 2021 conference in September. In fact, I’ve volunteered to co-author a panel there with some of my amazing fellow recipients. And the crowning achievement? Tonight, I passed my first GIAC certification (GSEC)!”

Despite these great results, we know there is still a lot of work to be done to help educate and develop a more inclusive information security workforce. So this year we are expanding the Security Trainings Scholarship Program to help us reach even more women and generate a steady stream of talent in the field of information security. This expansion would not have been possible without the added support of Facebook and Bloomberg, who have come on board this year to boost this important program.

“We are thrilled to scale the program this year, powered by scholarships from Google, Bloomberg, and Facebook,” said Dohm. “Now, more WiCyS members will be able to dive deep and change the trajectory of their career in less than a year, all within a cohort setting with extensive support and resources provided by mentors and colleagues. That’s what empowerment looks like, and we are thrilled that these three incredible strategic partners of WiCyS can make this happen for not only the WiCyS community, but also for the sake of the cybersecurity workforce at large.”

The next round of scholarships is open through August 2, 2021. To learn more and apply, please visit the WiCyS application page. We can’t wait to meet the next cohort of recipients.
Categories: Google Security Blog

Verifiable design in modern systems

Google Security Blog - Thu, 07/15/2021 - 1:18pm
Posted by Ryan Hurst, Production Security Team
The way we design and build software is continually evolving. Just as we now think of security as something we build into software from the start, we are also increasingly looking for new ways to minimize trust in that software. One of the ways we can do that is by designing software so that you can get cryptographic certainty of what the software has done.

In this post, we'll introduce the concept of verifiable data structures that help us get this cryptographic certainty. We'll describe some existing and new applications of verifiable data structures, and provide some additional resources we have created to help you use them in your own applications.
A verifiable data structure is a class of data structure that lets people efficiently agree, with cryptographic certainty, that the data contained within it is correct.

Merkle Trees are the most famous of these and have been used for decades because they can enable efficient verification that a particular piece of data is included among many records - as a result they also form the basis of most blockchains.

Although these verifiable data structures are not new, we now have a new generation of developers who have discovered them and the designs they enable -- further accelerating their adoption.
These verifiable data structures enable building a new class of software that have elements of verifiability and transparency built into the way they operate. This gives us new ways to defend against coercion, introduce accountability to existing and new ecosystems, and make it easier to demonstrate compliance to regulators, customers and partners.

Certificate Transparency is a great example of a non-blockchain use of these verifiable data structures at scale to secure core internet infrastructure. By using these patterns, we have been able to introduce transparency and accountability to an existing system used by everyone without breaking the web.
Unfortunately, despite the capabilities of verifiable data structures and the associated patterns, there are not many resources developers can use to design, build, and deploy scalable and production-quality systems based on them.

To address this gap we have generalized the platform we used to build Certificate Transparency so it can be applied to other classes of problems as well. Since this infrastructure has been used for years as part of this ecosystem it is well understood and can be deployed confidently in production systems.
This is why we have seen solutions in areas of healthcare, financial services, and supply chain leverage this platform. Beyond that, we have also applied these patterns to bring these transparency and accountability properties to other problems within our own products and services.

To this end, in 2019, we used this platform to bring supply chain integrity to the Go language ecosystem via the Go Checksum Database. This system allows developers to have confidence that the package management systems supporting the Go ecosystem can’t intentionally, arbitrarily, or accidentally start giving out the wrong code without getting caught. The reproducibility of Go builds makes this particularly powerful as it enables the developer to ensure what is in the source repository matches what is in the package management system. This solution delivers a verifiable chaiin all the way from the source repositories to the final compiled artifacts.

Another example of using these patterns is our recently announced partnership with the Linux Foundation on Sigstore. This project is a response to the ever-increasing influx of supply chain attacks on the Open Source ecosystem.

Supply chain attacks have been possible because there are weaknesses at every link in the chain. Components like build systems, source code management tools, and artifact repositories all need to be treated as critical production environments, because they are. To address this, we first need to make it possible to verify provenance along the entire chain and the goal of the Sigstore effort is to enable just that.

We are now working on using these patterns and tools to enable hardware-enforced supply chain integrity for device firmware, which we hope will discourage supply chain attacks on the devices, like smartphones, that we rely on every day by bringing transparency and accountability to their firmware supply chain.

In all of the above examples, we are using these verifiable data structures to ensure the integrity of artifacts in the supply chain. This enables customers, auditors, and internal security teams to be confident that each actor in the supply chain has lived up to their responsibilities. This helps earn the trust of those that rely on the supply chain, discourages insiders from using their position as it increases the chance they will get caught, introduces accountability, and enables proving the associated systems continually meet their compliance obligations.

When using these patterns the most important task is defining what data should be logged. This is why we put together a taxonomy and modeling framework which we have found to be helpful in designing verifiability into the systems we discussed above, and which we hope you will find valuable too.
Please take a look at the transparency.dev website to learn about these verifiable data structures, and the tools and guidance we have put together to help use them in your own applications.
Categories: Google Security Blog

Making the Internet more secure one signed container at a time

Google Security Blog - Mon, 07/12/2021 - 4:15pm
Posted by Priya Wadhwa, Jake Sanders, Google Open Source Security Team
With over 16 million pulls per month, Google’s `distroless` base images are widely used and depended on by large projects like Kubernetes and Istio. These minimal images don’t include common tools like shells or package managers, making their attack surface (and download size!) smaller than traditional base images such as `ubuntu` or `alpine`. Even with this additional protection, users could still fall prey to typosquatting attacks, or receive a malicious image if the distroless build process was compromised – making users vulnerable to accidentally using a malicious image instead of the actual distroless image. This problem isn’t unique to distroless images – until now, there just hasn’t been an easy way to verify that images are what they claim to be.

Introducing Cosign

Cosign simplifies signing and verifying container images, aiming to make signatures invisible infrastructure – basically, it takes over the hard part of signing and verifying software for you.

We developed cosign in collaboration with the sigstore project, a Linux Foundation project and a non-profit service that seeks to improve the open source software supply chain by easing the adoption of cryptographic software signing, backed by transparency log technologies.

We’re excited to announce that all of our distroless images are now signed by cosign! This means that all users of distroless can verify that they are indeed using the base image they intended to before kicking off image builds, making distroless images even more trustworthy. In fact, Kubernetes has already begun performing this check in their builds.

As we look to the future, Kubernetes SIG Release's vision is to establish a consumable, introspectable, and secure supply chain for the project. By collaborating with the sigstore maintainers (who are fellow Kubernetes contributors) to integrate signing and transparency into our supply chain, we hope to be an exemplar for standards in the cloud native (and wider) tech industry, said Stephen Augustus, co-chair for Kubernetes SIG Release.

How it works
To start signing distroless we integrated cosign into the distroless CI system, which builds and pushes images via Cloud Build. Signing every distroless image was as easy as adding an additional Cloud Build step to the Cloud Build job responsible for building and pushing the images. This additional step uses the cosign container image and a key pair stored in GCP KMS to sign every distroless image. With this additional signing step, users can now verify that the distroless image they’re running was built in the correct CI environment.


Right now, cosign can be run as an image or as a CLI tool. It supports:

  • Hardware and KMS signing
  • Bring-your-own PKI
  • Our free OIDC PKI (Fulcio)
  • Built-in binary transparency and timestamping service (Rekor)

Signing distroless with cosign is just the beginning, and we plan to incorporate other sigstore technologies into distroless to continue to improve it over the next few months. We also can’t wait to integrate sigstore with other critical projects. Stay tuned here for updates! To get started verifying your own distrolesss images, check out the distroless README and to learn more about sigstore, check out sigstore.dev.
Categories: Google Security Blog

Measuring Security Risks in Open Source Software: Scorecards Launches V2

Google Security Blog - Mon, 07/12/2021 - 4:14pm
Posted by Kim Lewandowski, Azeem Shaikh, Laurent Simon, Google Open Source Security Team

Contributors to the Scorecards project, an automated security tool that produces a “risk score” for open source projects, have accomplished a lot since our launch last fall. Today, in collaboration with the Open Source Security Foundation community, we are announcing Scorecards v2. We have added new security checks, scaled up the number of projects being scored, and made this data easily accessible for analysis.


With so much software today relying on open-source projects, consumers need an easy way to judge whether their dependencies are safe. Scorecards helps reduce the toil and manual effort required to continually evaluate changing packages when maintaining a project’s supply chain. Consumers can automatically assess the risks that dependencies introduce and use this data to make informed decisions about accepting these risks, evaluating alternative solutions, or working with the maintainers to make improvements.

Identifying Risks
Since last fall, Scorecards’ coverage has grown; we've added several new checks, following the Know, Prevent, Fix framework proposed by Google earlier this year, to prioritize our additions:

Malicious contributors

Contributors with malicious intent or compromised accounts can introduce potential backdoors into code. Code reviews help mitigate against such attacks. With the new Branch-Protection check, developers can verify that the project enforces mandatory code review from another developer before code is committed. Currently, this check can only be run by a repository admin due to GitHub API limitations. For a third-party repository, use the less informative Code-Review check instead.

Vulnerable code

Despite best efforts by developers and peer reviews, vulnerable code can enter source control and remain undetected. That’s why it's important to enable continuous fuzzing and static code analysis to catch bugs early in the development lifecycle. We have added checks to detect if a project uses Fuzzing and SAST tools as part of their CI/CD system.

Build system compromise

A common CI/CD solution used by GitHub projects is GitHub Actions. A danger with these action workflows is that they may handle untrusted user input. Meaning, an attacker can craft a malicious pull request to gain access to the privileged GitHub token, and with it the ability to push malicious code to the repo without review. To mitigate this risk, Scorecard's Token-Permissions prevention check now verifies that the GitHub workflows follow the principle of least privilege by making GitHub tokens read-only by default.

Bad dependencies

Any software is as secure as its weakest dependency. This may sound obvious, but the first step to knowing our dependencies is simply to declare them... and have our dependencies declare them too. Once we have this provenance information, we can assess the risks of our software and mitigate those risks. Unfortunately, there are several widely-used anti-patterns that break this provenance principle. The first of these anti-patterns is checked-in binaries -- as there's no way to easily verify or check the contents of the binary in the project. Scorecards provides Binary-Artifacts check for testing this.


Another anti-pattern is the use of curl | bash in scripts which dynamically pulls dependencies. Cryptographic hashes let us pin our dependencies to a known value: if this value ever changes, the build system will detect it and refuse to build. Pinning dependencies is useful everywhere we have dependencies: not just during compilation, but also in Dockerfiles, CI/CD workflows, etc. Scorecards checks for these anti-patterns with the Frozen-Deps check. This check is helpful for mitigating against malicious dependency attacks such as the recent CodeCov attack.


Even with hash-pinning, hashes need to be updated once in a while when dependencies patch vulnerabilities. Tools like dependabot or renovatebot give us the opportunity to review and update the hashes. The Scorecards Automated-Dependency-Update check verifies that developers rely on such tools to update their dependencies.


It is important to know vulnerabilities in a project before uptaking it as a dependency. Scorecards can provide this information via the new Vulnerabilities check, without the need to subscribe to a vulnerability alert system.

Scaling the impact
To date, the Scorecards project has scaled up to evaluate security criteria for over 50,000 open source projects. In order to scale this project, we undertook a massive redesign of our architecture and used a PubSub model which achieved horizontal scalability and higher throughput. This fully automated tool periodically evaluates critical open source projects and exposes the Scorecards check information through a public BigQuery dataset which is refreshed weekly.


This data can be retrieved using the bq command line tool. The following example shows how to export data for the Kubernetes project. Substitute the url for the repo to export data from a different project:

$ bq query --nouse_legacy_sql 'SELECT Repo, Date, Checks FROM openssf.scorecardcron.scorecard_latest WHERE Repo="github.com/kubernetes/kubernetes"'


To export the latest data on all analyzed projects, see instructions here.

How does the internet measure up?Scorecards data for available projects is now included in the recently announced Google Open Source Insights project and also showcased in OpenSSF Security Metrics project. The data on these sites shows that there are still important security gaps to fill, even in widely used packages like Kubernetes.


We also analyzed Scorecards data through Google Data Studio -- one of our data analysis and visualization tools.The diagram below shows a breakdown of the checks that were run and the pass/fail outcome for the 50,000 repositories:

 



As we can see, a lot needs to be done to improve the security of these critical projects. A large number of these projects are not continuously fuzzed, do not define a security policy for reporting vulnerabilities, and do not pin dependencies, to name just a few common problems. We all need to come together as an industry to drive awareness of these widespread security risks, and to make improvements that will benefit everyone.

Scorecards in ActionSeveral large projects have adopted Scorecards and are keeping us updated on their experiences with it. Below are some examples of Scorecards in action:

Envoy
Early on we talked about how the Envoy maintainers adopted Scorecards for their project and integrated it within their policy on introducing new dependencies. Since then, pull requests introducing new dependencies to Envoy must get approval from a dependency maintainer who uses Scorecards to evaluate the dependency against a set of criteria.

In addition, Envoy also got right to work in improving its own security health metrics according to its own Scorecards evaluation, and is now pinning C++ dependencies and requiring pip hashes for python dependencies. Github actions are also pinned in the continuous integration flow.

Previously, Envoy had created a tool that outputs Scorecards data on its dependencies as a CSV that can be used to generate a table of results:



Now with more project data, Envoy is able to automatically generate up-to-date Scorecard information about its dependencies and publish it in documentation, like the following:


Scorecards
We improved our own score for the Scorecards! For example, we are now pinning our own dependencies by hash (e.g. docker dependencies, workflow dependencies) to prevent CodeCov style attacks. We’ve also included a Security Policy based on this recommended template.
Get involvedWe look forward to continuing to grow the Scorecards community. The project now has contributions from 23 developers. Thank you to Azeem, Naveen, Laurent, Asra and Chris for their work building these new features and scaling Scorecards.

If you would like to join the fun, check out these good first timer issues.

If you would like us to help you run Scorecards on specific projects, please submit a GitHub pull request to add those projects here.

Last but not least, we have a lot of ideas and many more checks we’d like to add, but we want to hear from you. Tell us which checks you would like to see in the next version of Scorecards.
What’s next?
There are a couple of big enhancements we’re especially excited about:


Thanks again to the entire Scorecards community and the OpenSSF for making this project successful. If you’re adopting and improving the score of the projects you maintain, tell us about it. Until next time, keep on improving those scores!
Categories: Google Security Blog