Check Point Advisories

Multiple Vendor Telnet Client LINEMODE Buffer Overflow (CVE-2005-0469)

Vulnerability
Protection

Check Point Reference:	CPAI-2005-216
Date Published:	12 Oct 2009
Severity:	High
Last Updated:	Monday 12 October, 2009
Source:
Industry Reference:	CVE-2005-0469
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?
Vulnerability Description	The TELNET protocol is designed to provide a standard method of interfacing terminal devices and terminal-oriented processes to each other. It allows a computer to act as a remote terminal of another machine on a network. The TELNET protocol allows a user to connect to a remote host in order to control it. The remote host (which acts as a telnet server) accepts input directly from the user's computer (which acts as a telnet server) accepts input directly from the user's computer (which acts as a telnet client). This protocol is detailed documented in RFC854. A vulnerability exists in multiple vendor telnet client's processing of the LINEMODE sub-options. The vulnerable products improperly handle replies with a large number of SLC commands. An attacker may exploit this flaw to inject arbitrary code into the vulnerable telnet process. The vulnerable target will terminate upon processing of the malicious TELNET message. In a more sophisticated attack scenario, where arbitrary code is injected and executed on the target machine, the behaviour of the target is dependent on the intention of the malicious code.

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 Multiple Vendor Telnet Client LINEMODE 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: Telnet Enforcement Violation.
Attack Information: Multiple Vendor Telnet client LINEMODE buffer overflow