Enabling Firewall Bot protection prevent GrapheneOS Vanadium to access

Bot protection is unexpectedly blocking some browsers

  • Enabled Firewall Bot Protection as challenge mode on my project
  • Tried to access the site from a GrapheneOS Pixel7 phone, using Vanadium
  • Getting rejected after seing a screen like “verifying your browser”.

What I expect

I expect this browser to be able to reach the website with Bot Protection enabled. This browser is able to pass bot protections from Cloudflare. Why not Vercel? Shouldn’t we get a Captcha to solve in case the user-agent does not match? I actually just get rejected while Bot Protection is on. The anti-bot protection seems to think it is not a browser. But Vanadium might just block fingerprinting detection. This doesn’t mean the user trying to access the site is a bot. Many browsers actually blocks user-agent detection for privacy purposes and just serve random user-agent.

Real answer in this case would be to serve a captcha or something like that. But blocking with a screen saying Vercel blocks without any option doesn’t help an user getting unexpectedly blocked.

Step to reproduce

  • enable Firewall Bot Protection in challenge mode
  • try to reach the site using Vanadium on a mobile phone (or maybe any other browser blocking fingerprinting detection methods).

Anyone experiencing the same issue ?

Regards.