Patent ID: 7757287

Claim:
A method for maintaining computer security comprising: providing a signature file containing information about known system vulnerabilities, the information comprising a predefined length of a Universal Resource Locator (“URL”) for a message header, the predetermined length indicating a maximum amount of data that may be stored in a buffer of a web server; at a reverse proxy server residing between at least one client computer and the web server: receiving an incoming message from the at least one client computer, wherein the incoming message, if malicious and upon receipt by the web server, automatically causes the web server to perform an action which exploits a vulnerability of the web server; comparing a length of a URL in a message header of the incoming message (“the incoming URL”) with the predefined length in the signature file to determine whether the incoming message is malicious, wherein the length of the incoming URL indicates an amount of data that the incoming message will attempt to store on the buffer if the incoming message is received by the web server; and if the length of the incoming URL exceeds the predefined length, determining that the incoming message is malicious because the incoming message is capable of causing the buffer to overflow and blocking the incoming message from reaching the web server.