AIKIDO-2025-10329
joserfc is vulnerable to Authentication Bypass by Spoofing
30
Low Risk
This Affects:
joserfcTL;DR
Affected versions of this package are vulnerable to JWT (JSON Web Token) revocation bypass due to improper handling of non-canonical Base64 encoding in token validation. The revocation mechanism relies on exact string matching in a cache. However, without proper steganography validation, decoding methods may accept multiple encoding iterations of the same data. An attacker can exploit this by altering a revoked JWT's signature in a way that changes its encoding representation while preserving its decoded value, effectively bypassing revocation checks while still passing signature verification.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range.
Background info
joserfc is vulnerable to Authentication Bypass by Spoofing in versions 0.1.0 - 1.0.4.
How to fix this
Upgrade the joserfc library to the patch version.
Are You Affected?
Connect your repositories to instantly see whether vulnerable or malicious packages exist in your codebase.
Free. No credit card required.
SOC 2Compliant
ISO 27001Compliant