Check Point Advisories

Digium Asterisk SIP CSeq Heap Buffer Overflow

Vulnerability
Protection

Check Point Reference:	CPAI-2017-0480
Date Published:	7 Jun 2017
Severity:	Medium
Last Updated:	Tuesday 24 July, 2018
Source:	Digium
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	Digium Asterisk Open Source prior to 13.15.1 Digium Asterisk Open Source prior to 14.4.1 Digium Certified Asterisk prior to 13.13-cert4
Vulnerability Description	A heap-based buffer overflow vulnerability exists in Digium Asterisk. The vulnerability is due to a flaw while processing a very long CSeq header in SIP packet where Via header contains no branch parameter. A remote unauthenticated attacker can exploit this vulnerability by sending a crafted request to the Asterisk server.

Protection Overview

This protection detects attempts to exploit this vulnerability.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, click on Protection tab and select the version of your choice.

Security Gateway R80 / R77 / R75

In the IPS tab, click Protections and find the Digium Asterisk SIP CSeq Heap Buffer Overflow protection using the Search tool and Edit the protection's settings.
Install policy on all Security Gateways.

This protection's log will contain the following information:

Attack Name: VoIP Enforcement Violation.
Attack Information: Digium Asterisk SIP CSeq Heap Buffer Overflow