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Check Point FireWall-1 allows fragmented packets through firewall if Fast Mode is enabled

Vulnerability Note VU#446689

Original Release Date: 2001-01-05 | Last Revised: 2001-08-30

Overview

If any rules include the "Fast Mode" option, Check Point Firewall-1 and VPN-1 will incorrectly allow unauthorized connection attempts to hosts that should be restricted.

Description

A feature called "Fast Mode" (or "FASTPATH"), included in Check Point FireWall-1 and VPN-1 is designed to improve performance in older versions of these products. Unfortunately, a system with this feature enabled in any rules may not adequately protect systems from specially malformed TCP fragment packets. The Fast Mode feature is disabled by default. Specifically, an intruder can make unauthorized connection attempts to hosts they know the IP address for.

More information about this vulnerability is available from Check Point's web site:


The "Fast Mode" feature is scheduled to be discontinued in the next release of the Check Point FireWall-1 and VPN-1 products.

Impact

An intruder who knows the IP address of a protected host can make unauthorized connection attempts to the host.

Solution

Upgrade your product to version 4.1-SP3 or 4.0-SP8.

Turn off "Fast Mode" in all rule sets. This change is not needed if you upgrade to 4.1-SP3 or 4.0-SP8.

Vendor Information

446689
 

CVSS Metrics

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References

Acknowledgements

The information contained in this vulnerability note was obtained from the Check Point security advisory on this topic.

This document was written by Cory F Cohen.

Other Information

CVE IDs: None
Severity Metric: 26.04
Date Public: 2000-12-19
Date First Published: 2001-01-05
Date Last Updated: 2001-08-30 15:42 UTC
Document Revision: 8

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