Debian Security Advisory

DLA-345-1 strongswan -- LTS security update

Date Reported:
19 Nov 2015
Affected Packages:
Security database references:
In Mitre's CVE dictionary: CVE-2015-8023.
More information:

Tobias Brunner found an authentication bypass vulnerability in strongSwan, an IKE/IPsec suite.

Due to insufficient validation of its local state the server implementation of the EAP-MSCHAPv2 protocol in the eap-mschapv2 plugin can be tricked into successfully concluding the authentication without providing valid credentials.

It's possible to recognize such attacks by looking at the server logs. The following log message would be seen during the client authentication:

EAP method EAP_MSCHAPV2 succeeded, no MSK established