Cisco IOS 12.1T, 12.2, 12.2T, 12.3 and 12.3T, with Multi Protocol Label Switching (MPLS) installed but disabled, allows remote attackers to cause a denial of service (device reload) via a crafted packet sent to the disabled interface.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5662
https://exchange.xforce.ibmcloud.com/vulnerabilities/19071
http://www.us-cert.gov/cas/techalerts/TA05-026A.html
http://www.securityfocus.com/bid/12369
http://www.kb.cert.org/vuls/id/583638
http://www.cisco.com/warp/public/707/cisco-sa-20050126-les.shtml