Rule:--Sid:841--Summary:This event is generated when an attempt is made to exploit a known vulnerability in a CGI web application running on a server.--Impact:Information gathering and system integrity compromise. Possible unauthorizedadministrative access to the server or application. Possible executionof arbitrary code of the attackers choosing in some cases.--Detailed Information:This event is generated when an attempt is made to gain unauthorizedaccess to a CGI application running ona web server. Some applications donot perform stringent checks when validating the credentials of a clienthost connecting to the services offered on a host server. This can leadto unauthorized access and possibly escalated privileges to that of theadministrator. Data stored on the machine can be compromised and trustrelationships between the victim server and other hosts can be exploited by the attacker.If stringent input checks are not performed by the CGI application, itmay also be possible for an attacker to execute system binaries ormalicious code of the attackers choosing.--Affected Systems:	All systems running CGI applications--Attack Scenarios:An attacker can access an authentication mechanism and supply his/herown credentials to gain access. Alternatively the attacker can exploitweaknesses to gain access as the administrator by supplying input oftheir choosing to the underlying CGI script.--Ease of Attack:Simple. Exploits exist.--False Positives:None known.--False Negatives:None known.--Corrective Action:Ensure the system is using an up to date version of the software and hashad all vendor supplied patches applied.--Contributors:Sourcefire Research TeamBrian Caswell <bmc@sourcefire.com>Nigel Houghton <nigel.houghton@sourcefire.com>--Additional References:--