strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the internal buffer in charon-tkm's DH proxy. The earliest affected version is 5.3.0. An attack can occur via a crafted IKE_SA_INIT message.

strongSwan 5.9.8 and 5.9.9 potentially allows remote code execution because it uses a variable named "public" for two different purposes within the same function. There is initially incorrect access control, later followed by an expired pointer dereference. One attack vector is sending an untrusted client certificate during EAP-TLS. A server is affected only if it loads plugins that implement TLS-based EAP methods (EAP-TLS, EAP-TTLS, EAP-PEAP, or EAP-TNC). This is fixed in 5.9.10.