source: http://www.securityfocus.com/bid/2216/info

Apache Web Server 1.2 and previous versions are subject to a denial of service. By requesting a malformed GET request composed of an unusually large number of '/' characters, an attacker can cause CPU usage to spike. A restart of the service is required to gain normal functionality. 

https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/20558.zip