Asterisk IAX2 Call Number Exhaustion DoS

medium Nessus Plugin ID 40885


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


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.


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

See Also

Plugin Details

Severity: Medium

ID: 40885

File Name: asterisk_iax2_call_number_dos.nasl

Version: 1.17

Type: remote

Published: 9/8/2009

Updated: 11/15/2018

Risk Information


Risk Factor: Low

Score: 3.6


Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

Vulnerability Information

CPE: cpe:/a:asterisk:open_source

Required KB Items: Services/udp/iax2

Exploit Ease: No known exploits are available

Patch Publication Date: 9/3/2009

Vulnerability Publication Date: 6/12/2009

Reference Information

CVE: CVE-2009-2346

BID: 36275

CWE: 119

Secunia: 36593