source: http://www.securityfocus.com/bid/17439/info

PHP is prone to multiple 'safe_mode' and 'open_basedir' restriction-bypass vulnerabilities. Successful exploits could allow an attacker to access sensitive information or to write files in unauthorized locations.

These vulnerabilities would be an issue in shared-hosting configurations where multiple users can create and execute arbitrary PHP script code, when the 'safe_mode' and 'open_basedir' restrictions are expected to isolate the users from each other.

These issues are reported to affect PHP versions 4.4.2 and 5.1.2; other versions may also be vulnerable.

tempnam("path_from_open_basedir", "../../../../../../../../Open_basedir_bypasswd");