جزئیات آسیب‌پذیری

fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.3.0, fast-jwt createVerifier accepts a validly signed JWT whose payload is a JSON array because src/decoder.js checks that the payload is an object but does not reject arrays. The claim validator loop then finds no named exp, nbf, iss, aud, sub, jti, or nonce properties and silently skips those configured checks, returning the array as a successfully verified payload. An attacker who can produce or influence a validly signed token may bypass expiry, issuer, audience, subject, revocation, and replay protections. The opt-in requiredClaims option can block missing claims, and signature verification itself is not bypassed. This issue is fixed in version 6.3.0.

• https://github.com/nearform/fast-jwt/pull/639 x_refsource_MISC
• https://github.com/nearform/fast-jwt/commit/86e83efd8b5244f50859532d99244f0a9a9a4368 x_refsource_MISC
• https://github.com/nearform/fast-jwt/releases/tag/v6.3.0 x_refsource_MISC
• https://github.com/nearform/fast-jwt/security/advisories/GHSA-5hjw-83fp-phq9 x_refsource_CONFIRM