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.
We do not consider these to be security issues. For more details see http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=169857#c1
and http://www.php.net/security-note.php