Asterisk IAX2 Call Number Exhaustion DoS

This script is Copyright (C) 2009-2012 Tenable Network Security, Inc.


Synopsis :

The remote VoIP service is susceptible to a denial of service attack.

Description :

The version of Asterisk running on the remote host appears to be using
an older implementation of the IAX2 protocol that does not support
call token validation. Due to a design flaw in the protocol, a remote
attacker could send a large number of messages, exhausting all
available call numbers in the process. This would result in a denial
of service to legitimate users.

See also :

http://downloads.asterisk.org/pub/security/AST-2009-006.html
http://archives.neohapsis.com/archives/bugtraq/2009-09/0025.html

Solution :

Upgrade to the relevant version of Asterisk referenced in the
vendor's advisory.

Risk factor :

Medium / CVSS Base Score : 5.0
(CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P)
CVSS Temporal Score : 4.1
(CVSS2#E:F/RL:OF/RC:C)
Public Exploit Available : true

Family: Denial of Service

Nessus Plugin ID: 40885 (asterisk_iax2_call_number_dos.nasl)

Bugtraq ID: 36275

CVE ID: CVE-2009-2346