Improper Verification of Cryptographic Signature Affecting lemur package, versions [,1.9.2)

lemur is a Certificate management and orchestration service

Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature in the decode_with_multiple_secrets process. An attacker can influence the cryptographic algorithm used for token verification by supplying a crafted JWT with a chosen alg header value. This allows the attacker to bypass intended algorithm restrictions and potentially forge tokens if a separate configuration disclosure exposes the signing secret. This is only exploitable if the attacker is able to obtain the signing secret through an independent disclosure or if the deployment migrates to asymmetric signing without correcting the algorithm selection logic.

• GitHub Advisory
• GitHub Release