Check Point Advisories

Dnsmasq TFTP Service Remote Heap Buffer Overflow (CVE-2009-2957)

Vulnerability
Protection

Check Point Reference:	CPAI-2009-422
Date Published:	9 Feb 2010
Severity:	High
Last Updated:	Tuesday 09 February, 2010
Source:
Industry Reference:	CVE-2009-2957
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?
Vulnerability Description	Dnsmasq is a lightweight DNS forwarder and DHCP server, designed to provide DNS (and optionally DHCP) services to a small-scale network. Dnsmasq supports static and dynamic DHCP leases and BOOTP/TFTP/PXE for network booting of diskless machines. It includes a secure, read-only, TFTP server to allow net/PXE boot of DHCP hosts. A heap based buffer overflow vulnerability has been reported in Dnsmasq. The vulnerability is due to improper bounds checking when handling TFTP requests. A remote attacker can exploit this vulnerability by sending a specially crafted packet to the target server. Successful exploitation of this vulnerability can lead to arbitrary code execution within the security context of the affected service. An unsuccessful code execution attempt can lead to abnormal termination of the vulnerable program.

Protection Overview

This protection will detect and block 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 Dnsmasq TFTP Service Remote 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: TFTP Enforcement Violation.
Attack Information: Dnsmasq TFTP service remote heap buffer overflow