Zeus web server allows remote attackers to view the source code for CGI programs via a null character (%00) at the end of a URL.
https://exchange.xforce.ibmcloud.com/vulnerabilities/3982
https://euvd.enisa.europa.eu/vulnerability/EUVD-2000-0148
http://www.securityfocus.com/bid/977
http://archives.neohapsis.com/archives/bugtraq/2000-02/0057.html