freeradius -- arbitrary code execution for TLS-based authentication

freeRADIUS security team reports:

Overflow in EAP-TLS for 2.1.10, 2.1.11 and 2.1.12.
The issue was found by Timo Warns, and communicated to
[email protected]. A sample exploit for the issue was
included in the notification.
The vulnerability was created in commit a368a6f4f4aaf on
August 18, 2010. Vulnerable versions include 2.1.10, 2.1.11,
and 2.1.12. Also anyone running the git “master” branch
after August 18, 2010 is vulnerable.
All sites using TLS-based EAP methods and the above
versions are vulnerable. The only configuration change which
can avoid the issue is to disable EAP-TLS, EAP-TTLS, and
PEAP.
An external attacker can use this vulnerability to
over-write the stack frame of the RADIUS server, and cause
it to crash. In addition, more sophisticated attacks may
gain additional privileges on the system running the RADIUS
server.
This attack does not require local network access to the
RADIUS server. It can be done by an attacker through a WiFi
Access Point, so long as the Access Point is configured to
use 802.1X authentication with the RADIUS server.