Double free vulnerability in the session extension in PHP 5.2.0 and 5.2.1 allows context-dependent attackers to execute arbitrary code via illegal characters in a session identifier, which is rejected by an internal session storage module, which calls the session identifier generator with an improper environment, leading to code execution when the generator is interrupted, as demonstrated by triggering a memory limit violation or certain PHP errors.

Directory traversal vulnerability in the posix_access function in PHP 5.2.6 and earlier allows remote attackers to bypass safe_mode restrictions via a .. (dot dot) in an http URL, which results in the URL being canonicalized to a local filename after the safe_mode check has successfully run.

Integer overflow in the str_replace function in PHP 4.4.5 and PHP 5.2.1 allows context-dependent attackers to have an unknown impact via a single character search string in conjunction with a single character replacement string, which causes an "off by one overflow."

The dechunk filter in PHP 5.3 through 5.3.2, when decoding an HTTP chunked encoding stream, allows context-dependent attackers to cause a denial of service (crash) and possibly trigger memory corruption via a negative chunk size, which bypasses a signed comparison, related to an integer overflow in the chunk size decoder.

Format string vulnerability in the zend_throw_or_error function in Zend/zend_execute_API.c in PHP 7.x before 7.0.1 allows remote attackers to execute arbitrary code via format string specifiers in a string that is misused as a class name, leading to incorrect error handling.

exif.c in the Exif extension in PHP before 5.3.6 on 64-bit platforms performs an incorrect cast, which allows remote attackers to cause a denial of service (application crash) via an image with a crafted Image File Directory (IFD) that triggers a buffer over-read.

Multiple stack-based buffer overflows in the phar_set_inode function in phar_internal.h in PHP before 5.4.40, 5.5.x before 5.5.24, and 5.6.x before 5.6.8 allow remote attackers to execute arbitrary code via a crafted length value in a (1) tar, (2) phar, or (3) ZIP archive.

The phpinfo implementation in ext/standard/info.c in PHP before 5.4.30 and 5.5.x before 5.5.14 does not ensure use of the string data type for the PHP_AUTH_PW, PHP_AUTH_TYPE, PHP_AUTH_USER, and PHP_SELF variables, which might allow context-dependent attackers to obtain sensitive information from process memory by using the integer data type with crafted values, related to a "type confusion" vulnerability, as demonstrated by reading a private SSL key in an Apache HTTP Server web-hosting environment with mod_ssl and a PHP 5.3.x mod_php.

** DISPUTED ** Untrusted search path vulnerability in the installation functionality in PHP 5.3.17, when installed in the top-level C:\ directory, might allow local users to gain privileges via a Trojan horse DLL in the C:\PHP directory, which may be added to the PATH system environment variable by an administrator, as demonstrated by a Trojan horse wlbsctrl.dll file used by the "IKE and AuthIP IPsec Keying Modules" system service in Windows Vista SP1, Windows Server 2008 SP2, Windows 7 SP1, and Windows 8 Release Preview. NOTE: CVE disputes this issue because the unsafe PATH is established only by a separate administrative action that is not a default part of the PHP installation.

Integer overflow in the substr_compare function in PHP 5.2.1 and earlier allows context-dependent attackers to read sensitive memory via a large value in the length argument, a different vulnerability than CVE-2006-1991.

The var_export function in PHP 5.2 before 5.2.14 and 5.3 before 5.3.3 flushes the output buffer to the user when certain fatal errors occur, even if display_errors is off, which allows remote attackers to obtain sensitive information by causing the application to exceed limits for memory, execution time, or recursion.

Use-after-free vulnerability in the CURLFile implementation in ext/curl/curl_file.c in PHP before 5.6.27 and 7.x before 7.0.12 allows remote attackers to cause a denial of service or possibly have unspecified other impact via crafted serialized data that is mishandled during __wakeup processing.

The WDDX deserializer in the wddx extension in PHP 5 before 5.2.1 and PHP 4 before 4.4.5 does not properly initialize the key_length variable for a numerical key, which allows context-dependent attackers to read stack memory via a wddxPacket element that contains a variable with a string name before a numerical variable.

Buffer overflows in (1) php_mime_split in PHP 4.1.0, 4.1.1, and 4.0.6 and earlier, and (2) php3_mime_split in PHP 3.0.x allows remote attackers to execute arbitrary code via a multipart/form-data HTTP POST request when file_uploads is enabled.

ext/standard/var_unserializer.re in PHP 7.0.x before 7.0.21 and 7.1.x before 7.1.7 is prone to a heap use after free while unserializing untrusted data, related to the zval_get_type function in Zend/zend_types.h. Exploitation of this issue can have an unspecified impact on the integrity of PHP.

** DISPUTED ** The _zval_get_long_func_ex in Zend/zend_operators.c in PHP 7.1.2 allows attackers to cause a denial of service (NULL pointer dereference and application crash) via crafted use of "declare(ticks=" in a PHP script. NOTE: the vendor disputes the classification of this as a vulnerability, stating "Please do not request CVEs for ordinary bugs. CVEs are relevant for security issues only."

In PHP versions before 7.4.31, 8.0.24 and 8.1.11, the phar uncompressor code would recursively uncompress "quines" gzip files, resulting in an infinite loop.

ext/standard/var_unserializer.re in PHP before 5.6.26 mishandles object-deserialization failures, which allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via an unserialize call that references a partially constructed object.

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.

The GENERATE_SEED macro in PHP 4.x before 4.4.8 and 5.x before 5.2.5, when running on 64-bit systems, performs a multiplication that generates a portion of zero bits during conversion due to insufficient precision, which produces 24 bits of entropy and simplifies brute force attacks against protection mechanisms that use the rand and mt_rand functions.