Cisco IOS XR Software SNMP Management Plane Protection ACL Bypass Vulnerability

A vulnerability in the UDP forwarding code of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to bypass configured management plane protection policies and access the Simple Network Management Plane (SNMP) server of an affected device.

This vulnerability is due to incorrect UDP forwarding programming when using SNMP with management plane protection. An attacker could exploit this vulnerability by attempting to perform an SNMP operation using broadcast as the destination address that could be processed by an affected device that is configured with an SNMP server. A successful exploit could allow the attacker to communicate to the device on the configured SNMP ports. Although an unauthenticated attacker could send UDP datagrams to the configured SNMP port, only an authenticated user can retrieve or modify data using SNMP requests.

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-snmp-uhv6ZDeF [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snmp-uhv6ZDeF”]

This advisory is part of the March 2024 release of the Cisco IOS XR 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 XR Software Security Advisory Bundled Publication [“https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75299”].