Debian Security Advisory DSA 2665-1 (strongswan - Authentication Bypass) Network Vulnerability

Summary

Kevin Wojtysiak discovered a vulnerability in strongSwan, an IPsec based VPN solution. When using the OpenSSL plugin for ECDSA based authentication, an empty, zeroed or otherwise invalid signature is handled as a legitimate one. An attacker could use a forged signature to authenticate like a legitimate user and gain access to the VPN (and everything protected by this). While the issue looks like CVE-2012-2388 (RSA signature based authentication bypass), it is unrelated.

Solution

For the stable distribution (squeeze), this problem has been fixed in version 4.4.1-5.3. For the testing distribution (wheezy), this problem has been fixed in version 4.5.2-1.5+deb7u1. For the unstable distribution (sid), this problem has been fixed in version 4.6.4-7. We recommend that you upgrade your strongswan packages.

Insight

The strongSwan VPN suite is based on the IPsec stack in standard Linux 2.6 kernels. It supports both the IKEv1 and IKEv2 protocols.

Affected

strongswan on Debian Linux

Detection

This check tests the installed software version using the apt package manager.

References