Cisco IOS XE Software for ASR 1000 Series Aggregation Services Routers IPv6 Multicast Denial of Service Vulnerability

A vulnerability in the Multicast Leaf Recycle Elimination (mLRE) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition.

This vulnerability is due to incorrect handling of certain IPv6 multicast packets when they are fanned out more than seven times on an affected device. An attacker could exploit this vulnerability by sending a specific IPv6 multicast or IPv6 multicast VPN (MVPNv6) packet through the affected device. A successful exploit could allow the attacker to cause a reload of the affected device, resulting in a 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-mlre-H93FswRz [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-mlre-H93FswRz”]

This advisory is part of the September 2023 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: September 2023 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication [“https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74916”].