OpenBSD ISAKMPD Security Association Piggyback Delete Payload Denial Of Service Vulnerability

OpenBSD ISAKMPD Security Association Piggyback Delete Payload Denial Of Service Vulnerability

It is reported that OpenBSD's isakmpd daemon is susceptible to a remote denial of service vulnerability.

An attacker is able to delete security associations and policies from IPSec VPN's by sending a malformed UDP ISAKMP packet to a vulnerable server. The malformed packet contains payloads for both setting up a new tunnel and deleting a tunnel. Isakmpd improperly acts upon the delete payload and terminates the associations and policys relating to the tunnel.

It is possible to destroy security associations, effectively eliminating the VPN connection between gateways, denying service to legitimate users of the VPN.