search menu icon-carat-right cmu-wordmark

CERT Coordination Center

Cisco IPS fails to properly check fragmented IP packets

Vulnerability Note VU#658884

Original Release Date: 2006-09-20 | Last Revised: 2006-09-20

Overview

Cisco IPS systems may fail to check specially-crafted IP packets that are fragmented.

Description

Some Cisco intrusion prevention system (IPS) products can be configured as passive intrusion detection systems (IDS) or active IPS systems. Cisco refers to the IPS mode as "inline" and the IDS mode as "promiscuous".

An attacker may be able to create a stream of specially crafted fragmented IP packets that are not processed by the IPS. This would allow an attacker to generate malicious traffic that evades IPS inspection.

Impact

IPS products in inline mode may allow malicious traffic to pass through them. IPS products in promiscuous mode may not detect malicious traffic.

Solution

Upgrade
Cisco has released an update that addresses this issue. See Cisco Security Advisory cisco-sa-20060920-ips for more details.

Vendor Information

658884
 
Affected   Unknown   Unaffected

Cisco Systems, Inc.

Updated:  September 20, 2006

Status

  Vulnerable

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

See http://www.cisco.com/warp/public/707/cisco-sa-20060920-ips.shtml for more details.

If you have feedback, comments, or additional information about this vulnerability, please send us email.


CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A

References

Acknowledgements

Cisco credits Pratap Ramamurthy and Shai Rubin for reporting this vulnerability.

This document was written by Ryan Giobbi.

Other Information

CVE IDs: None
Severity Metric: 4.59
Date Public: 2006-09-20
Date First Published: 2006-09-20
Date Last Updated: 2006-09-20 19:11 UTC
Document Revision: 16

Sponsored by the Department of Homeland Security Office of Cybersecurity and Communications.