The (1) file_exists and (2) imap_reopen functions in PHP before 5.1.5 do not check for the safe_mode and open_basedir settings, which allows local users to bypass the settings. NOTE: the error_log function is covered by CVE-2006-3011, and the imap_open function is covered by CVE-2006-1017.
http://www.vupen.com/english/advisories/2006/3318
http://www.ubuntu.com/usn/usn-342-1
http://www.securityfocus.com/bid/19582
http://www.php.net/release_5_1_5.php
http://www.novell.com/linux/security/advisories/2006_52_php.html
http://www.mandriva.com/security/advisories?name=MDKSA-2006:162
http://secunia.com/advisories/22039
http://secunia.com/advisories/21842