Check Point Advisories

Digium Asterisk UDPTL Processing Heap Buffer Overflow

Vulnerability
Protection

Check Point Reference:	CPAI-2011-233
Date Published:	27 Apr 2011
Severity:	High
Last Updated:	Sunday 20 June, 2021
Source:
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?
Vulnerability Description	Asterisk is an open source software implementation of a telephone private branch exchange (PBX). A remote, unauthenticated attacker can exploit this vulnerability to overflow the buffer and execute code on the vulnerable system. If code execution is unsuccessful, this can lead to a denial of service condition. A heap buffer overflow vulnerability has been found in Digium Asterisk while handling UDPTL packets. A buffer overflow vulnerability exists in Digium Asterisk. The vulnerability is due to a bounds checking errors while handling UDPTL packets. Successful exploitation might lead to code being executed on the vulnerable system in the context of the vulnerable service, usually Asterisk. If code execution is unsuccessful, this can lead to a denial of service condition.

Protection Overview

This protection will detect and block malicicious UDPTL requests sent to the vulnerable server.

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 R81 / R80 / R77 / R75

In the IPS tab, click Protections and find the Digium Asterisk UDPTL Processing 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 UDPTL Processing Heap Buffer Overflow