Multiple versions of Cisco ONS 15327, ONS 15454, and ONS 15454 SDH, including 4.1(0) to 4.1(2), 4.5(x), 4.0(0) to 4.0(2), and earlier versions, allows remote attackers to cause a denial of service (control card reset) via malformed SNMP packets.
https://exchange.xforce.ibmcloud.com/vulnerabilities/16765
https://euvd.enisa.europa.eu/vulnerability/EUVD-2004-1431
http://www.securityfocus.com/bid/10768
http://www.kb.cert.org/vuls/id/548968
http://www.cisco.com/warp/public/707/cisco-sa-20040721-ons.shtml