CVE-2025-53940

Description

Quiet is an alternative to team chat apps like Slack, Discord, and Element that does not require trusting a central server or running one's own. In versions 6.1.0-alpha.4 and below, Quiet's API for backend/frontend communication was using an insecure, not constant-time comparison function for token verification. This allowed for a potential timing attack where an attacker would try different token values and observe tiny differences in the response time (wrong characters fail faster) to guess the whole token one character at a time. This is fixed in version 6.0.1.

Weakness Type (CWE)

CWE-208 CWE-208

References

Other References

https://github.com/TryQuiet/quiet/issues/2820#issue-3021080269 https://github.com/TryQuiet/quiet/pull/2928 https://github.com/TryQuiet/quiet/security/advisories/GHSA-gpw8-w78h-xj67

Frequently Asked Questions

What is CVE-2025-53940? +

Quiet is an alternative to team chat apps like Slack, Discord, and Element that does not require trusting a central server or running one's own. In versions 6.1.0-alpha.4 and below, Quiet's API for backend/frontend communication was using an insecure, not constant-time comparison function for token verification. This allowed for a potential timing attack where an attacker would try different token values and observe tiny differences in the response time (wrong characters fail faster) to guess the whole token one character at a time. This is fixed in version 6.0.1.

How do I check if I'm vulnerable to CVE-2025-53940? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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