joaquimserafim/json-web-token is a javascript library use to interact with JSON Web Tokens (JWT) which are a compact URL-safe means of representing claims to be transferred between two parties. Affected versions of the json-web-token library are vulnerable to a JWT algorithm confusion attack. On line 86 of the 'index.js' file, the algorithm to use for verifying the signature of the JWT token is taken from the JWT token, which at that point is still unverified and thus shouldn't be trusted. To exploit this vulnerability, an attacker needs to craft a malicious JWT token containing the HS256 algorithm, signed with the public RSA key of the victim application. This attack will only work against this library is the RS256 algorithm is in use, however it is a best practice to use that algorithm.

Token validation methods are susceptible to a timing side-channel during HMAC comparison. With a large enough number of requests over a low latency connection, an attacker may use this to determine the expected HMAC.

An issue was discovered in drf-jwt 1.15.x before 1.15.1. It allows attackers with access to a notionally invalidated token to obtain a new, working token via the refresh endpoint, because the blacklist protection mechanism is incompatible with the token-refresh feature. NOTE: drf-jwt is a fork of jpadilla/django-rest-framework-jwt, which is unmaintained.