Race condition in the symlink function in PHP 5.1.6 and earlier allows local users to bypass the open_basedir restriction by using a combination of symlink, mkdir, and unlink functions to change the file path after the open_basedir check and before the file is opened by the underlying system, as demonstrated by symlinking a symlink into a subdirectory, to point to a parent directory via .. (dot dot) sequences, and then unlinking the resulting symlink.

PHP 4.x up to 4.4.4 and PHP 5 up to 5.1.6 allows local users to bypass certain Apache HTTP Server httpd.conf options, such as safe_mode and open_basedir, via the ini_restore function, which resets the values to their php.ini (Master Value) defaults.

Multiple heap-based buffer overflows in the (1) str_repeat and (2) wordwrap functions in ext/standard/string.c in PHP before 5.1.5, when used on a 64-bit system, have unspecified impact and attack vectors, a different vulnerability than CVE-2006-1990.

The cURL extension files (1) ext/curl/interface.c and (2) ext/curl/streams.c in PHP before 5.1.5 permit the CURLOPT_FOLLOWLOCATION option when open_basedir or safe_mode is enabled, which allows attackers to perform unauthorized actions, possibly related to the realpath cache.

The error_log function in basic_functions.c in PHP before 4.4.4 and 5.x before 5.1.5 allows local users to bypass safe mode and open_basedir restrictions via a "php://" or other scheme in the third argument, which disables safe mode.

The c-client library 2000, 2001, or 2004 for PHP before 4.4.4 and 5.x before 5.1.5 do not check the (1) safe_mode or (2) open_basedir functions, and when used in applications that accept user-controlled input for the mailbox argument to the imap_open function, allow remote attackers to obtain access to an IMAP stream data structure and conduct unauthorized IMAP actions.