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: $Revision: 1.15 $

Type: remote

Published: 2009/09/08

Modified: 2016/11/15

Dependencies: 20834

Risk Information

Risk Factor: Medium


Base Score: 5

Temporal Score: 3.9

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

Temporal Vector: CVSS2#E:POC/RL:OF/RC:C

Vulnerability Information

CPE: cpe:/a:asterisk:open_source

Required KB Items: Services/udp/iax2

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2009/09/03

Vulnerability Publication Date: 2009/06/12

Reference Information

CVE: CVE-2009-2346

BID: 36275

OSVDB: 57762

EDB-ID: 8940

Secunia: 36593

CWE: 119