University of Washington IMAP Toolkit 2007f on UNIX, as used in imap_open() in PHP and other products, launches an rsh command (by means of the imap_rimap function in c-client/imap4r1.c and the tcp_aopen function in osdep/unix/tcp_unix.c) without preventing argument injection, which might allow remote attackers to execute arbitrary OS commands if the IMAP server name is untrusted input (e.g., entered by a user of a web application) and if rsh has been replaced by a program with different argument semantics. For example, if rsh is a link to ssh (as seen on Debian and Ubuntu systems), then the attack can use an IMAP server name containing a "-oProxyCommand" argument.
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").
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.
The Apache2 component in PHP before 5.6.38, 7.0.x before 7.0.32, 7.1.x before 7.1.22, and 7.2.x before 7.2.10 allows XSS via the body of a "Transfer-Encoding: chunked" request, because the bucket brigade is mishandled in the php_handler function in sapi/apache2handler/sapi_apache2.c.
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.
An issue was discovered in PHP 7.3.x before 7.3.0alpha3, 7.2.x before 7.2.8, and before 7.1.20. The php-fpm master process restarts a child process in an endless loop when using program execution functions (e.g., passthru, exec, shell_exec, or system) with a non-blocking STDIN stream, causing this master process to consume 100% of the CPU, and consume disk space with a large volume of error logs, as demonstrated by an attack by a customer of a shared-hosting facility.
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.
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.
PHP through 7.1.11 enables potential SSRF in applications that accept an fsockopen or pfsockopen hostname argument with an expectation that the port number is constrained. Because a :port syntax is recognized, fsockopen will use the port number that is specified in the hostname argument, instead of the port number in the second argument of the function.
Buffer overflow in the radius_get_vendor_attr function in the Radius extension before 1.2.7 for PHP allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a large Vendor Specific Attributes (VSA) length value.