strongSwan 4.3.5 through 5.0.3, when using the OpenSSL plugin for ECDSA signature verification, allows remote attackers to authenticate as other users via an invalid signature.
The GMP Plugin in strongSwan 4.2.0 through 4.6.3 allows remote attackers to bypass authentication via a (1) empty or (2) zeroed RSA signature, aka "RSA signature verification vulnerability."