Security vulnerabilities and automated fixes for jwt issues
7 posts found
A critical authentication bypass vulnerability was discovered in `backend/services/auth-state.js` where the `tokenTtlSeconds()` function used `jwt.decode()` instead of `jwt.verify()`, allowing attackers to forge JWT tokens with arbitrary claims. Because `jwt.decode()` never validates the cryptographic signature, any attacker could craft a token with a manipulated expiration time or elevated privileges and have it accepted as legitimate. The fix replaces the insecure decode call with `jwt.verify(
A critical authentication bypass was discovered in `JwtExtractor.java` where `JWT.decode()` was used instead of a proper signature-verifying method, allowing any attacker to forge a JWT with an arbitrary username — including `admin` — and gain unauthorized access. The fix adds clear documentation establishing the trust boundary: signature validation must occur upstream, and the extracted claims are for display purposes only. This change prevents the class from being misused as an authorization g
A critical authentication bypass in the `/api/posts` endpoint allowed any unauthenticated user to create, update, or delete posts without verification. The POST endpoint had zero authentication checks, while PUT and DELETE endpoints used a trivially bypassable username comparison that attackers could forge by simply including the target username in their request body. The fix validates user identity by looking up the userId in the database before any post operations.
A critical authentication bypass vulnerability in PyJWT 2.12.1 allowed attackers to forge valid JSON Web Tokens, potentially bypassing application authentication mechanisms entirely. The vulnerability was fixed in PyJWT 2.13.0 through security improvements to token validation logic. This fix is essential for any application relying on JWT-based authentication.
A critical authentication bypass vulnerability was discovered in a dashboard application where JWT tokens could be forged due to improper validation. The vulnerability affected multiple routes including backup, live chat, and authentication endpoints, potentially allowing attackers to access sensitive operations without proper authorization. This fix demonstrates why robust JWT validation is essential for API security.
A critical authentication vulnerability was discovered where the jsonwebtoken library was being used without explicitly specifying allowed algorithms during token verification. This oversight enables attackers to exploit algorithm confusion attacks, potentially forging valid tokens by manipulating the algorithm header to 'none' or switching from asymmetric to symmetric algorithms, completely bypassing authentication controls.
A medium-severity vulnerability (CVE-2026-24842) in node-tar allowed attackers to bypass hardlink security checks and create arbitrary files through path traversal attacks. This vulnerability, combined with improper configuration management storing JWT secrets in plaintext .env files, created a dangerous attack vector for token forgery and unauthorized access.