Libreswan: Denial of service

Background

Libreswan is a free software implementation of the most widely supported and standarized VPN protocol based on (“IPsec”) and the Internet Key Exchange (“IKE”).

Description

As a result of a bug in handling certain bogus encrypted IKEv1, while building a log message that the packet has been dropped, a NULL pointer dereference causes Libreswan to crash and restart when it attempts to log the state name involved.

Impact

An attacker could cause a possible Denial of Service condition.

Workaround

There is no known workaround at this time.

Resolution

All Libreswan users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-vpn/libreswan-3.32"