Cisco Security Advisory – Cisco Routers running Internetwork Operating System (IOS) that supports Multi Protocol Label Switching (MPLS) are vulnerable to a Denial of Service (DoS) attack on MPLS disabled interfaces. A system that supports MPLS is vulnerable even if that system is not configured for MPLS. The vulnerability is only present in Cisco IOS release trains based on 12.1T, 12.2, 12.2T, 12.3 and 12.3T. Releases based on 12.1 mainline, 12.1E and all releases prior to 12.1 are not vulnerable.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/35915/cisco-sa-20050126-les.txt
Source: https://packetstormsecurity.com/files/35915/Cisco-Security-Advisory-20050126-les.html