Debian Security Advisory

DLA-244-1 strongswan -- LTS security update

Date Reported:
12 Jun 2015
Affected Packages:
Security database references:
In Mitre's CVE dictionary: CVE-2015-4171.
More information:

Alexander E. Patrakov discovered an issue in strongSwan, an IKE/IPsec suite used to establish IPsec protected links.

When a client authenticate the server with certificates and the client authenticates using pre-shared key or EAP, the constraints on the server certificate are only enforced by the client after all authentication steps are completed successfully. A rogue server which can authenticate using a valid certificate issued by any CA trusted by the client could trick the user into continuing the authentication, revealing the username and password digest (for EAP) or even the cleartext password (if EAP-GTC is accepted).