GEN:SID 1:1506
Message WEB-CGI alchemy http server NUL arbitrary command execution attempt
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 unauthorized
administrative access to the server or application. Possible execution
of arbitrary code of the attackers choosing in some cases.
Detailed Information This event is generated when an attempt is made to gain unauthorized
access to a CGI application running ona web server. Some applications do
not perform stringent checks when validating the credentials of a client
host connecting to the services offered on a host server. This can lead
to unauthorized access and possibly escalated privileges to that of the
administrator. Data stored on the machine can be compromised and trust
relationships between the victim server and other hosts can be exploited by the attacker.

If stringent input checks are not performed by the CGI application, it
may also be possible for an attacker to execute system binaries or
malicious code of the attackers choosing.
Affected Systems All systems running CGI applications
Attack Scenarios An attacker can access an authentication mechanism and supply his/her
own credentials to gain access. Alternatively the attacker can exploit
weaknesses to gain access as the administrator by supplying input of
their choosing to the underlying CGI script.
Ease of Attack Simple. Exploits exist.
Corrective Action Ensure the system is using an up to date version of the software and has
had all vendor supplied patches applied.
Additional References  
Rule References bugtraq: 3599
cve: 2001-0871