Integer overflow in PHP 5 up to 5.1.6 and 4 before 4.3.0 allows remote attackers to execute arbitrary code via an argument to the unserialize PHP function with a large value for the number of array elements, which triggers the overflow in the Zend Engine ecalloc function (Zend/zend_alloc.c).
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.
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.
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.
Buffer overflow in the LWZReadByte_ function in ext/gd/libgd/gd_gif_in.c in the GD extension in PHP before 5.1.5 allows remote attackers to have an unknown impact via a GIF file with input_code_size greater than MAX_LWZ_BITS, which triggers an overflow when initializing the table array.
Integer overflow in memory allocation routines in PHP before 5.1.6, when running on a 64-bit system, allows context-dependent attackers to bypass the memory_limit restriction.
PHP before 4.4.3 and 5.x before 5.1.4 does not limit the character set of the session identifier (PHPSESSID) for third party session handlers, which might make it easier for remote attackers to exploit other vulnerabilities by inserting PHP code into the PHPSESSID, which is stored in the session file. NOTE: it could be argued that this not a vulnerability in PHP itself, rather a design limitation that enables certain attacks against session handlers that do not account for this limitation.