SITIC Vulnerability Advisory – Apache 2.0.x suffers from a buffer overflow when expanding environment variables in configuration files such as .htaccess and httpd.conf. In a setup typical of ISPs, for instance, users are allowed to configure their own public_html directories with .htaccess files, leading to possible privilege escalation.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/34376/SA04-002.txt
Source: https://packetstormsecurity.com/files/34376/SITIC-Security-Advisory-2004.2.html