> Firefox was not selected at random. It was chosen because it is a widely deployed and deeply scrutinized open source project — an ideal proving ground for a new class of defensive tools. What I was thinking was, "Chromium team is definitely not going to collaborate with us because they have Gemini, while Safari belongs to a company that operates in a notoriously secretive way when it comes to product development."
Hardening Firefox with Anthropic's Red Team
31–40 of 188 posts
Re: Hardening Firefox with Anthropic's Red Team
#32Re: Hardening Firefox with Anthropic's Red Team
#33It's interesting that they counted these as security vulnerabilities (from the linked Anthropic article) > “Crude” is an important caveat here. The exploits Claude wrote only worked on our testing environment, which intentionally removed some of the security features found in modern browsers. This includes, most importantly, the sandbox, the purpose of which is to reduce the impact of these types of vulnerabilities.…
[Work at Anthropic, used to work at Mozilla.] Firefox has never required a full chain exploit in order to consider something a vulnerability. A large proportion of disclosed Firefox vulnerabilities are vulnerabilities in the sandboxed process. If you look at Firefox's Security Severity Rating doc: https://wiki.mozilla.org/Security_Severity_Ratings/Client what you'll see is that vulnerabilities within the sandbox, and…
Re: Hardening Firefox with Anthropic's Red Team
#34And this is a good reminder for me to add a prompt about property testing being preferred over straight unit tests and maybe to create a prompt for fuzz testing the code when we hit Ready state.
Re: Hardening Firefox with Anthropic's Red Team
#35I've had mixed results. I find that agents can be great for: 1. Producing new tests to increase coverage. Migrating you to property testing. Setting up fuzzing. Setting up more static analysis tooling. All of that would normally take "time" but now it's a background task. 2. They can find some vulnerabilities. They are "okay" at this, but if you are willing to burn tokens then it's fine. 3. They are absolutely wrong…
Re: Hardening Firefox with Anthropic's Red Team
#36Re: Hardening Firefox with Anthropic's Red Team
#37I've had mixed results. I find that agents can be great for: 1. Producing new tests to increase coverage. Migrating you to property testing. Setting up fuzzing. Setting up more static analysis tooling. All of that would normally take "time" but now it's a background task. 2. They can find some vulnerabilities. They are "okay" at this, but if you are willing to burn tokens then it's fine. 3. They are absolutely wrong…
I've personally used two AI-first static analysis security tools and found great results, including interesting business logic issues, across my employers SaaS tech stack. We integrated one of the tools. I look forward to getting employer approval to say which, but that hasn't happened yet, sadly.
Re: Hardening Firefox with Anthropic's Red Team
#38Re: Hardening Firefox with Anthropic's Red Team
#39It's interesting that they counted these as security vulnerabilities (from the linked Anthropic article) > “Crude” is an important caveat here. The exploits Claude wrote only worked on our testing environment, which intentionally removed some of the security features found in modern browsers. This includes, most importantly, the sandbox, the purpose of which is to reduce the impact of these types of vulnerabilities.…
Re: Hardening Firefox with Anthropic's Red Team
#40Perhaps I missed it but I don't see any false positives mentioned.
That's because there were none. All bugs came with verifiable testcases (crash tests) that crashed the browser or the JS shell.
For the JS shell, similar to fuzzing, a small fraction of these bugs were bugs in the shell itself (i.e. testing only) - but according to our fuzzing guidelines, these are not false positives and they will also be fixed.