PHP » PHP : Security Vulnerabilities (Denial of service)

In PHP 8.0.X before 8.0.28, 8.1.X before 8.1.16 and 8.2.X before 8.2.3, excessive number of parts in HTTP form upload can cause high resource consumption and excessive number of log entries. This can cause denial of service on the affected server by exhausting CPU resources or disk space. 

In PHP versions 7.4.x below 7.4.30, 8.0.x below 8.0.20, and 8.1.x below 8.1.7, when using Postgres database extension, supplying invalid parameters to the parametrized query may lead to PHP attempting to free memory using uninitialized data as pointers. This could lead to RCE vulnerability or denial of service.

In PHP versions 7.3.x below 7.3.29, 7.4.x below 7.4.21 and 8.0.x below 8.0.8, when using Firebird PDO driver extension, a malicious database server could cause crashes in various database functions, such as getAttribute(), execute(), fetch() and others by returning invalid response data that is not parsed correctly by the driver. This can result in crashes, denial of service or potentially memory corruption.

A use-after-free in onig_new_deluxe() in regext.c in Oniguruma 6.9.2 allows attackers to potentially cause information disclosure, denial of service, or possibly code execution by providing a crafted regular expression. The attacker provides a pair of a regex pattern and a string, with a multi-byte encoding that gets handled by onig_new_deluxe(). Oniguruma issues often affect Ruby, as well as common optional libraries for PHP and Rust.

ext/imap/php_imap.c in PHP 5.x and 7.x before 7.3.0 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via an empty string in the message argument to the imap_mail function.

ext/standard/var_unserializer.c in PHP 5.x through 7.1.24 allows attackers to cause a denial of service (application crash) via an unserialize call for the com, dotnet, or variant class.

ext/standard/var.c in PHP 5.x through 7.1.24 on Windows allows attackers to cause a denial of service (NULL pointer dereference and application crash) because com and com_safearray_proxy return NULL in com_properties_get in ext/com_dotnet/com_handlers.c, as demonstrated by a serialize call on COM("WScript.Shell").

exif_process_IFD_in_MAKERNOTE in ext/exif/exif.c in PHP before 5.6.37, 7.0.x before 7.0.31, 7.1.x before 7.1.20, and 7.2.x before 7.2.8 allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted JPEG file.

An issue was discovered in PHP before 5.6.36, 7.0.x before 7.0.30, 7.1.x before 7.1.17, and 7.2.x before 7.2.5. ext/ldap/ldap.c allows remote LDAP servers to cause a denial of service (NULL pointer dereference and application crash) because of mishandling of the ldap_get_dn return value.

In PHP before 5.6.31, 7.x before 7.0.21, and 7.1.x before 7.1.7, a stack-based buffer overflow in the zend_ini_do_op() function in Zend/zend_ini_parser.c could cause a denial of service or potentially allow executing code. NOTE: this is only relevant for PHP applications that accept untrusted input (instead of the system's php.ini file) for the parse_ini_string or parse_ini_file function, e.g., a web application for syntax validation of php.ini directives.

In PHP 7.x before 7.0.21 and 7.1.x before 7.1.7, ext/intl/msgformat/msgformat_parse.c does not restrict the locale length, which allows remote attackers to cause a denial of service (stack-based buffer overflow and application crash) or possibly have unspecified other impact within International Components for Unicode (ICU) for C/C++ via a long first argument to the msgfmt_parse_message function.

In PHP before 5.6.31, 7.x before 7.0.17, and 7.1.x before 7.1.3, remote attackers could cause a CPU consumption denial of service attack by injecting long form variables, related to main/php_variables.c.

An issue was discovered in Oniguruma 6.2.0, as used in Oniguruma-mod in Ruby through 2.4.1 and mbstring in PHP through 7.1.5. A SIGSEGV occurs in left_adjust_char_head() during regular expression compilation. Invalid handling of reg->dmax in forward_search_range() could result in an invalid pointer dereference, normally as an immediate denial-of-service condition.

PHP 7.x through 7.1.5 allows remote attackers to cause a denial of service (buffer overflow and application crash) or possibly have unspecified other impact via a long string because of an Integer overflow in mysqli_real_escape_string.

The i_zval_ptr_dtor function in Zend/zend_variables.h in PHP 7.1.5 allows attackers to cause a denial of service (memory consumption and application crash) or possibly have unspecified other impact by triggering crafted operations on array data structures.

The zend_string_extend function in Zend/zend_string.h in PHP through 7.1.5 does not prevent changes to string objects that result in a negative length, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact by leveraging a script's use of .= with a long string.

** DISPUTED ** The GNU Multiple Precision Arithmetic Library (GMP) interfaces for PHP through 7.1.4 allow attackers to cause a denial of service (memory consumption and application crash) via operations on long strings. NOTE: the vendor disputes this, stating "There is no security issue here, because GMP safely aborts in case of an OOM condition. The only attack vector here is denial of service. However, if you allow attacker-controlled, unbounded allocations you have a DoS vector regardless of GMP's OOM behavior."

** 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."

Zend/zend_hash.c in PHP before 7.0.15 and 7.1.x before 7.1.1 mishandles certain cases that require large array allocations, which allows remote attackers to execute arbitrary code or cause a denial of service (integer overflow, uninitialized memory access, and use of arbitrary destructor function pointers) via crafted serialized data.

The php_wddx_pop_element function in ext/wddx/wddx.c in PHP 7.0.x before 7.0.15 and 7.1.x before 7.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via an inapplicable class name in a wddxPacket XML document, leading to mishandling in a wddx_deserialize call.

The object_common1 function in ext/standard/var_unserializer.c in PHP before 5.6.30, 7.0.x before 7.0.15, and 7.1.x before 7.1.1 allows remote attackers to cause a denial of service (buffer over-read and application crash) via crafted serialized data that is mishandled in a finish_nested_data call.

Off-by-one error in the phar_parse_pharfile function in ext/phar/phar.c in PHP before 5.6.30 and 7.0.x before 7.0.15 allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via a crafted PHAR archive with an alias mismatch.

Integer overflow in the phar_parse_pharfile function in ext/phar/phar.c in PHP before 5.6.30 and 7.0.x before 7.0.15 allows remote attackers to cause a denial of service (memory consumption or application crash) via a truncated manifest entry in a PHAR archive.

The exif_convert_any_to_int function in ext/exif/exif.c in PHP before 5.6.30, 7.0.x before 7.0.15, and 7.1.x before 7.1.1 allows remote attackers to cause a denial of service (application crash) via crafted EXIF data that triggers an attempt to divide the minimum representable negative integer by -1.

The unserialize implementation in ext/standard/var.c in PHP 7.x before 7.0.14 allows remote attackers to cause a denial of service (use-after-free) or possibly have unspecified other impact via crafted serialized data. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-6834.