Verification Bypass

Overview

Versions 4.2.1 and earlier of jsonwebtoken are affected by a verification bypass vulnerability. This is a result of weak validation of the JWT algorithm type, occuring when an attacker is allowed to arbitrarily specify the JWT algorithm.

Recommendation

Update to version 4.2.2 or later.

References

• [1] https://github.com/auth0/node-jsonwebtoken/commit/1bb584bc382295eeb7ee8c4452a673a77a68b687
• https://www.timmclean.net/2015/02/25/jwt-alg-none.html
• https://auth0.com/blog/2015/03/31/critical-vulnerabilities-in-json-web-token-libraries/
• GitHub Advisory