Check Point Advisories

SpamAssassin Long Message Header Denial of Service (CVE-2005-3351)

Vulnerability
Protection

Check Point Reference:	CPAI-2005-335
Date Published:	11 Feb 2010
Severity:	High
Last Updated:	Thursday 11 February, 2010
Source:
Industry Reference:	CVE-2005-3351
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?
Vulnerability Description	SpamAssassin is an open source spam filtering product developed using Perl. The product supports a number of filtering methods such as header fields and body phrase identification, white and black list rules. The product is also embedded in numerous commercial anti-spam products from a broad range of vendors. There exists a remote denial of service vulnerability in Apache SpamAssassin. The vulnerability is caused by an inefficient method used in email header parsing. An attacker can exploit the vulnerability by sending a malicious email that contains crafted headers. This can cause the affected application to terminate. As SpamAssassin may be set up in numerous configurations, the behavior of the affected program is dependent on the current setup. If SpamAssassin is running as a standalone daemon, a successful attack will terminate the process creating a denial-of-service condition of the spam filtering functionality. This might affect email delivery if SpamAssassin is configured as a mandatory step in the delivery path. When the product is set up as a standalone filter, filtering email through a Local Delivery Agent (procmail), an offensive email will be discarded. In this case, the email will not be delivered to the intended recipient nor will it be stored as an identified spam email.

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 SpamAssassin Long Message Header Denial of Service 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: SMTP Protection Violation.
Attack Information: SpamAssassin long message header denial of service