New versions of Asterisk were released today that fix a security vulnerability in the IAX2 channel driver:
The Asterisk Development Team today released Asterisk 184.108.40.206 and Asterisk 220.127.116.11 to address a security vulnerability in the IAX2 channel driver (chan_iax2). The vulnerability affects all users with IAX2 clients that might be compromised or used by a malicious user, and can lead to denial of service attacks and random Asterisk server crashes via a relatively trivial exploit.
All users are urged to upgrade as soon as they can practically do so, or ensure that they don’t expose IAX2 services to the public if it is not necessary.
Slightly more detail about the flaw is available in the Changelog:
* channels/chan_iax2.c: ensure that the received number of bytes is included in all IAX2 incoming frame analysis checks (fixes a known vulnerability)