The Cisco Optical Service Module (OSM) for the Catalyst 6500 and 7600 series running Cisco IOS 12.1(8)E through 12.1(13.4)E allows remote attackers to cause a denial of service (hang) via a malformed packet.
https://exchange.xforce.ibmcloud.com/vulnerabilities/10823
http://www.securityfocus.com/bid/6358
http://www.cisco.com/warp/public/707/osm-lc-ios-pkt-vuln-pub.shtml