Cisco IOS Software DLSw Information Disclosure Vulnerability

A vulnerability in the DLSw feature of Cisco IOS could allow an unauthenticated, remote attacker to extract information from previously processed packets.

The vulnerability is due to the lack of initialization of packet buffers. An attacker could exploit this vulnerability by connecting to the DLSw port (TCP/2067). An exploit could allow the attacker to extract potentially sensitive information, including clear-text passwords and SNMP community strings from previously processed packets.

This vulnerability was reported to Cisco by Tate Hansen and John McLeod of FishNet Security, and Kyle Rainey.

Cisco has confirmed the vulnerability in a security notice and released software updates.

To exploit this vulnerability, an attacker need to be able to connect to the DLSw port on a targeted device which may require access to trusted, internal networks. In addition, the attacker may need to acquire additional information about the device such as whether or not DLSw is enabled. These requirements may reduce 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.