libreswan 3.9 through 3.12 allows remote attackers to cause a denial of service (daemon restart) via an IKEv1 packet with (1) unassigned bits set in the IPSEC DOI value or (2) the next payload value set to ISAKMP_NEXT_SAK.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.