A bug in the standard library ScalarMult implementation of curve P-256 for amd64 architectures in Go before 1.7.6 and 1.8.x before 1.8.2 causes incorrect results to be generated for specific input points. An adaptive attack can be mounted to progressively extract the scalar input to ScalarMult by submitting crafted points and observing failures to the derive correct output. This leads to a full key recovery attack against static ECDH, as used in popular JWT libraries.

An issue was discovered in Pivotal PCF Elastic Runtime 1.6.x versions prior to 1.6.60, 1.7.x versions prior to 1.7.41, 1.8.x versions prior to 1.8.23, and 1.9.x versions prior to 1.9.1. Incomplete validation logic in JSON Web Token (JWT) libraries can allow unprivileged attackers to impersonate other users in multiple components included in PCF Elastic Runtime, aka an "Unauthenticated JWT signing algorithm in multiple components" issue.

An issue was discovered in Cloud Foundry Foundation routing-release versions prior to 0.142.0 and cf-release versions 203 to 231. Incomplete validation logic in JSON Web Token (JWT) libraries can allow unprivileged attackers to impersonate other users to the routing API, aka an "Unauthenticated JWT signing algorithm in routing" issue.

The verify function in Encryption/Symmetric.php in Malcolm Fell jwt before 1.0.3 does not use a timing-safe function for hash comparison, which allows attackers to spoof signatures via a timing attack.

JWT.php in F21 JWT before 2.0 allows remote attackers to bypass signature verification via crafted tokens.