Multiple buffer overflows in PHP before 5.2.1 allow attackers to cause a denial of service and possibly execute arbitrary code via unspecified vectors in the (1) session, (2) zip, (3) imap, and (4) sqlite extensions; (5) stream filters; and the (6) str_replace, (7) mail, (8) ibase_delete_user, (9) ibase_add_user, and (10) ibase_modify_user functions. NOTE: vector 6 might actually be an integer overflow (CVE-2007-1885). NOTE: as of 20070411, vector (3) might involve the imap_mail_compose function (CVE-2007-1825).

Buffer underflow in PHP before 5.2.1 allows attackers to cause a denial of service via unspecified vectors involving the sapi_header_op function.

Unspecified vulnerability in PHP before 5.2.1 allows attackers to "clobber" certain super-global variables via unspecified vectors.

PHP before 5.2.1 allows attackers to bypass safe_mode and open_basedir restrictions via unspecified vectors in the session extension. NOTE: it is possible that this issue is a duplicate of CVE-2006-6383.

Unspecified vulnerabilities in PHP, probably before 5.2.0, allow local users to bypass open_basedir restrictions and perform unspecified actions via unspecified vectors involving the (1) chdir and (2) tempnam functions. NOTE: the tempnam vector might overlap CVE-2006-1494.

Buffer overflow in PHP before 5.2.0 allows remote attackers to execute arbitrary code via crafted UTF-8 inputs to the (1) htmlentities or (2) htmlspecialchars functions.

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.

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.