source: https://www.securityfocus.com/bid/1036/info

A vulnerability exists in the default installation of Caldera OpenLinux 2.3. A CGI is installed in /home/httpd/cgi-bin/ names rpm_query. Any user can run this CGI and obtain a listing of the packages, and versions of packages, installed on this system. This could be used to determine vulnerabilities on the machine remotely.

Run the rpm_query CGI via a GET. It is located in /cgi-bin/rmp_query, relative to the root of the web server.