This indicates a potentially malicious attempt to execute commands on an Apache Web Server.
Apache Web Server is an open source solution to building a secure modern web server that is compatible with both UNIX and Windows operating systems. Due to inadequate user input checking, a remote attacker can execute arbitrary commands on a target system by sending it a specially crafted message.
Any unprotected Apache HTTP Server versions 1.3.23 and earlier or versions 2.0.28 Beta is vulnerable to the attack.
Attackers can execute arbitrary commands on the victim system.
Update to Apache Group Apache 1.3.24 or newer.