Cisco IPS systems may fail to check specially-crafted IP packets that are fragmented.
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.
IPS products in inline mode may allow malicious traffic to pass through them. IPS products in promiscuous mode may not detect malicious traffic.
Cisco credits Pratap Ramamurthy and Shai Rubin for reporting this vulnerability.
This document was written by Ryan Giobbi.
|Date First Published:||2006-09-20|
|Date Last Updated:||2006-09-20 19:11 UTC|