Vulnerabilidades de Nearform

fast-jwt provides fast JSON Web Token (JWT) implementation. From 6.2.0 until 6.3.0, fast-jwt can misclassify RSA public-key text as an HMAC secret when the key has non-whitespace content before its PEM header. In src/crypto.js, performDetectPublicKeyAlgorithms trims whitespace but publicKeyPemMatcher remains start-anchored, so comments, control characters, zero-width characters, or wrapper text can prevent PEM detection and reach the HMAC fallback. An attacker who knows the public key bytes can sign arbitrary HS256 claims with that public material when HS256 is inferred or allowed, resulting in authentication or authorization bypass. An asymmetric-only algorithm allowlist prevents the attack. This issue is fixed in version 6.3.0.

fast-jwt fornece uma implementação rápida de JSON Web Tokens (JWT). Antes da versão 6.2.4, uma vulnerabilidade crítica de bypass de autenticação no fluxo de resolvedor de chaves assíncrono do fast-jwt permite que qualquer atacante não autenticado forje JWTs arbitrários que são aceitos como autênticos. Quando o resolvedor de chaves da aplicação retorna uma string vazia (''), por exemplo por meio do fallback estilo JWKS keys[decoded.header.kid] || '', o fast-jwt a converte em um Buffer de comprimento zero, a passa para crypto.createSecretKey, deriva allowedAlgorithms = ['HS256','HS384','HS512'] a partir dela e então verifica a assinatura do token contra um HMAC com chave vazia. O atacante simplesmente calcula HMAC-SHA256(key='', input='${header}.${payload}'), que o Node aceita sem reclamar, e o verificador retorna o payload escolhido pelo atacante (sub, admin, scopes etc.) como autêntico. Esta vulnerabilidade está corrigida na versão 6.2.4.

fast-jwt provides fast JSON Web Token (JWT) implementation. From 0.0.1 to before 6.2.0, setting up a custom cacheKeyBuilder method which does not properly create unique keys for different tokens can lead to cache collisions. This could cause tokens to be mis-identified during the verification process leading to valid tokens returning claims from different valid tokens and users being mis-identified as other users based on the wrong token. Version 6.2.0 contains a patch.

fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, the publicKeyPemMatcher regex in fast-jwt/src/crypto.js uses a ^ anchor that is defeated by any leading whitespace in the key string, re-enabling the exact same JWT algorithm confusion attack that CVE-2023-48223 patched.

get-jwks contains fetch utils for JWKS keys. In versions prior to 11.0.2, a vulnerability in get-jwks can lead to cache poisoning in the JWKS key-fetching mechanism. When the iss (issuer) claim is validated only after keys are retrieved from the cache, it is possible for cached keys from an unexpected issuer to be reused, resulting in a bypass of issuer validation. This design flaw enables a potential attack where a malicious actor crafts a pair of JWTs, the first one ensuring that a chosen public key is fetched and stored in the shared JWKS cache, and the second one leveraging that cached key to pass signature validation for a targeted iss value. The vulnerability will work only if the iss validation is done after the use of get-jwks for keys retrieval. This issue has been patched in version 11.0.2.