PHP through 7.0.8 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and therefore does not protect applications from the presence of untrusted client data in the HTTP_PROXY environment variable, which might allow remote attackers to redirect an application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, as demonstrated by (1) an application that makes a getenv('HTTP_PROXY') call or (2) a CGI configuration of PHP, aka an "httpoxy" issue.

In PHP versions 8.1.* before 8.1.30, 8.2.* before 8.2.24, 8.3.* before 8.3.12, when using a certain non-standard configurations of Windows codepages, the fixes for  CVE-2024-4577 https://github.com/advisories/GHSA-vxpp-6299-mxw3  may still be bypassed and the same command injection related to Windows "Best Fit" codepage behavior can be achieved. This may allow a malicious user to pass options to PHP binary being run, and thus reveal the source code of scripts, run arbitrary PHP code on the server, etc.

FrankenPHP is a modern application server for PHP. From version 1.11.2 to before version 1.12.3, the splitPos() function in cgi.go misuses golang.org/x/text/search with search.IgnoreCase when the request path contains a non-ASCII byte. Two distinct flaws in that fallback let an attacker mislead FrankenPHP into treating a non-.php file as a .php script. In any deployment where the attacker can place content into a file served by FrankenPHP (uploads, file storage, etc.), this can be escalated to remote code execution by crafting a URL whose path triggers either flaw. This issue has been patched in version 1.12.3.

In PHP versions 8.3.* before 8.3.19 and 8.4.* before 8.4.5, a code sequence involving __set handler or ??=  operator and exceptions can lead to a use-after-free vulnerability. If the third party can control the memory layout leading to this, for example by supplying specially crafted inputs to the script, it could lead to remote code execution.

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.

The init_request_info function in sapi/cgi/cgi_main.c in PHP before 5.2.6 does not properly consider operator precedence when calculating the length of PATH_TRANSLATED, which might allow remote attackers to execute arbitrary code via a crafted URI.

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.

In PHP from 8.1.* before 8.1.32, from 8.2.* before 8.2.28, from 8.3.* before 8.3.19, from 8.4.* before 8.4.5, when parsing HTTP redirect in the response to an HTTP request, there is currently limit on the location value size caused by limited size of the location buffer to 1024. However as per RFC9110, the limit is recommended to be 8000. This may lead to incorrect URL truncation and redirecting to a wrong location.

In PHP versions prior to 7.4.33, 8.0.25 and 8.1.12, when using imageloadfont() function in gd extension, it is possible to supply a specially crafted font file, such as if the loaded font is used with imagechar() function, the read outside allocated buffer will be used. This can lead to crashes or disclosure of confidential information. 

PHP before 5.2.12 and 5.3.x before 5.3.1 does not restrict the number of temporary files created when handling a multipart/form-data POST request, which allows remote attackers to cause a denial of service (resource exhaustion), and makes it easier for remote attackers to exploit local file inclusion vulnerabilities, via multiple requests, related to lack of support for the max_file_uploads directive.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in yuv_ensure_buffer() in libfreerdp/codec/h264.c, h264->width and h264->height are updated before the reallocation loop. If any winpr_aligned_recalloc() call fails, the function returns FALSE but width/height are already inflated. This issue has been patched in version 3.24.2.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in resize_vbar_entry() in libfreerdp/codec/clear.c, vBarEntry->size is updated to vBarEntry->count before the winpr_aligned_recalloc() call. If realloc fails, size is inflated while pixels still points to the old, smaller buffer. On a subsequent call where count <= size (the inflated value), realloc is skipped. The caller then writes count * bpp bytes of attacker-controlled pixel data into the undersized buffer, causing a heap buffer overflow. This issue has been patched in version 3.24.2.