The Siemens SpeedStream 6520 router allows remote attackers to cause a denial of service (web interface crash) via an HTTP request to basehelp_English.htm with a large integer in the Content-Length field.
https://exchange.xforce.ibmcloud.com/vulnerabilities/41123
http://www.securityfocus.com/bid/28490
http://www.securityfocus.com/archive/1/489009/100/0/threaded