Cisco IPS Intrusion Detection System Module contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition on a targeted device. Updates are not available.
A vulnerability in the IDSM-2 drivers could allow an unauthenticated, remote attacker to cause the system kernel to become unresponsive. This creates a denial of service (DoS) condition because the Cisco IPS sensor is not able to execute several critical tasks, including alert notification, event store management, sensor authentication, and traffic inspection. The Cisco IPS web server will also be unavailable.
The vulnerability is due to improper handling of malformed TCP packets from the management interface of the affected system. An attacker may exploit this vulnerability by sending malformed IP packets to the management interface. A TCP three-way handshake is not required to exploit this vulnerability. A hard system reboot is needed to restore the functionality of the system.
The vulnerability can be triggered only by IPv4 traffic directed to the management interface. Traffic passing through the sensing interfaces will not trigger this vulnerability.
Cisco has confirmed the vulnerability in a security advisory; however, software updates are not available.
The following versions of Cisco Catalyst 6500 Series IDSM-2 are affected:
5.0, 5.0(1), 5.0(2), 5.0(3), 5.0(4), 5.0(5), and 5.0(6)
To exploit this vulnerability, an attacker may require access to trusted, internal networks to send crafted requests to the affected software. This access requirement could limit the likelihood of a successful exploit.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
Prevent disruption of communication between devices by reducing the impact of attacks which may directly impact the CPU performance of the individual devices. For control plane hardening best practices, see the Cisco Guide to Harden Cisco IOS Devices.
Understanding activity on the network provides information and visibility that can be used to identify potential security incidents. Organizations should log events from devices and review the logged data to provide insight into anomalies or malicious activity. For logging best practices, see the Cisco Guide to Harden Cisco IOS Devices.
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