An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemblev2incomingfragments() would ignore unknown outer payloads but still store these in a fixed size array msgdigest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md->digestroof < elemsof(md->digest)) causes the daemon to abort. No remote code execution is possible. Any configuration that allows IKEv2 connections that do not set fragmentation=no are vulnerable. IKEv1 is not affected.

An issue was discovered in Libreswan before 4.12. When an IKEv1 Quick Mode connection configured with IDIPV4ADDR or IDIPV6ADDR receives an IDcr payload with IDFQDN a NULL pointer dereference causes a crash and restart of the pluto daemon. NOTE: the earliest affected version is 4.6.