Digium Asterisk 1.8/10/11 TCP Session SIP/HTTP/XMPP memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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A vulnerability has been found in Digium Asterisk 1.8/10/11 (Communications System) and classified as critical. Affected by this vulnerability is an unknown function of the component TCP Session Handler. The manipulation as part of a SIP/HTTP/XMPP leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The software performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect availability.

The weakness was released 01/02/2013 by Walter Doekes as AST-2012-014 as confirmed advisory (Website). It is possible to read the advisory at downloads.asterisk.org. The public release was coordinated with Digium. This vulnerability is known as CVE-2012-5976 since 11/21/2012. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are unknown but a public exploit is available. In the case of TCP, since multiple packets in a stream may be concatenated together, this can lead to large allocations that overflow the stack.

It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 56 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 72054 (GLSA-201401-15 : Asterisk: Multiple vulnerabilities), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Gentoo Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 42397 (Asterisk Multiple Denial of Service Vulnerabilities (AST-2012-014, AST-2012-015)).

Upgrading to version, 10.11.1 or 11.1.2 eliminates this vulnerability. The upgrade is hosted for download at downloads.asterisk.org. A possible mitigation has been published immediately after the disclosure of the vulnerability. For SIP, the allocation now has an upper limit. For HTTP, the allocation is now a heap allocation instead of a stack allocation. For XMPP, the allocation has been eliminated since it was unnecessary.

The vulnerability is also documented in the vulnerability database at Tenable (72054). Entries connected to this vulnerability are available at 7232 and 7246.






  • open-source

CPE 2.3info

CPE 2.2info


VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 6.7

VulDB Base Score: 7.5
VulDB Temp Score: 6.7
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Class: Memory corruption
CWE: CWE-119
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept

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Nessus ID: 72054
Nessus Name: GLSA-201401-15 : Asterisk: Multiple vulnerabilities
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OpenVAS ID: 892605
OpenVAS Name: Debian Security Advisory DSA 2605-2 (asterisk - several issues
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Threat Intelligenceinfo

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Recommended: Upgrade
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Upgrade: Asterisk


11/07/2012 🔍
11/21/2012 +14 days 🔍
01/02/2013 +42 days 🔍
01/02/2013 +0 days 🔍
01/02/2013 +0 days 🔍
01/02/2013 +0 days 🔍
01/03/2013 +1 days 🔍
01/04/2013 +1 days 🔍
01/21/2014 +382 days 🔍
04/20/2021 +2646 days 🔍


Vendor: digium.com

Advisory: AST-2012-014
Researcher: Walter Doekes
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2012-5976 (🔍)

SecurityTracker: 1027931 - Asterisk Stack Allocation Overflow Lets Remote Users Deny Service
SecurityFocus: 57095 - Astium PBX Denial of Service Vulnerability
Secunia: 51689 - Asterisk Multiple Vulnerabilities, Highly Critical

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍


Created: 01/03/2013 07:05 PM
Updated: 04/20/2021 02:12 PM
Changes: 01/03/2013 07:05 PM (81), 12/24/2017 09:34 AM (5), 04/20/2021 02:12 PM (8)
Complete: 🔍


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