2039134 - Firefox intermittently failing Cloudflare PQC X25519MLKEM768 key agreement test (falling back to X25519)

Status: UNCONFIRMED

(Firefox :: General, defect)

Description

[pennypacker71]

Attachment: Fail - X25519.png

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:150.0) Gecko/20100101 Firefox/150.0

Steps to reproduce:

Ran the Cloudflare test (https://pq.cloudflareresearch.com) in Firefox multiple times by doing repeated hard refreshes (Ctrl+Shift+R). Ran the same test in Chrome and Edge on the same computer/network/ISP.

Actual results:

Firefox: Quite often the result is: "You are using X25519 which is not post-quantum secure" (fail). Sometimes it's around 10 fails out of 50 hard refreshes, other times it's 1 out of 50. It seems random. Sometimes the very first run after opening Firefox gives the X25519 (failing) result. Tried changing internet connection from home Wi-Fi to cellular Wi-Fi hotspot but same results. Disabling Norton 360 firewall had no effect on results.

Chrome and Edge: Consistently passing: "You are using X25519MLKEM768 which is post-quantum secure", without a fail observed in several hundreds of hard refreshes.

Expected results:

Firefox should consistently pass regardless of number of hard refreshes.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Networking: HTTP' component, but is not confident enough to move the bug to that component.