Asterisk IAX2 Multiple Method Handshake Spoofing DoS

medium Nessus Plugin ID 32132


The remote VoIP service can be abused to conduct an amplification attack against third-party hosts.


The version of Asterisk running on the remote host does not properly validate an IAX2 handshake. By spoofing NEW and ACK messages, an unauthenticated, remote attacker may be able to leverage this issue to flood a third-party host with packets from the affected host containing audio data.


Upgrade to Asterisk 1.4.20 / 1.2.28, Asterisk Business Edition C.1.8.1 / B.2.5.2, AsteriskNOW 1.0.3, s800i (Asterisk Appliance) or later.

See Also

Plugin Details

Severity: Medium

ID: 32132

File Name: asterisk_iax2_spoofed_handshake.nasl

Version: 1.21

Type: remote

Published: 5/6/2008

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: 4/22/2008

Reference Information

CVE: CVE-2008-1897, CVE-2008-1923

BID: 28901

CWE: 16, 287

Secunia: 29927