Cisco IOS 11.1(x) through 11.3(x) and 12.0(x) through 12.2(x), when configured for BGP routing, allows remote attackers to cause a denial of service (device reload) via malformed BGP (1) OPEN or (2) UPDATE messages.
https://exchange.xforce.ibmcloud.com/vulnerabilities/16427
http://www.kb.cert.org/vuls/id/784540
http://www.cisco.com/warp/public/707/cisco-sa-20040616-bgp.shtml