Cisco IOS XE Software Auxiliary Asynchronous Port Denial of Service Vulnerability

A vulnerability in auxiliary asynchronous port (AUX) functions of Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload or stop responding.

This vulnerability is due to the incorrect handling of specific ingress traffic when flow control hardware is enabled on the AUX port. An attacker could exploit this vulnerability by reverse telnetting to the AUX port and sending specific data after connecting. A successful exploit could allow the attacker to cause the device to reset or stop responding, resulting in a denial of service (DoS) condition.

Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability.

This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aux-333WBz8f [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aux-333WBz8f”]

This advisory is part of the March 2024 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: March 2024 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication [“https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75056”].