PHP — популярный язык сценариев общего назначения, особенно подходящий для веб-разработки.

The pcre_compile2 function in PCRE before 8.37 allows context-dependent attackers to compile incorrect code and cause a denial of service (out-of-bounds read) via regular expression with a group containing both a forward referencing subroutine call and a recursive back reference, as demonstrated by "((?+1)(\1))/".

The compile_branch function in PCRE before 8.37 allows context-dependent attackers to compile incorrect code, cause a denial of service (out-of-bounds heap read and crash), or possibly have other unspecified impact via a regular expression with a group containing a forward reference repeated a large number of times within a repeated outer group that has a zero minimum quantifier.

In PHP versions 7.3.x below 7.3.13 and 7.4.0 on Windows, when supplying custom headers to mail() function, due to mistake introduced in commit 78f4b4a2dcf92ddbccea1bb95f8390a18ac3342e, if the header is supplied in lowercase, this can result in double-freeing certain memory locations.

When PHP EXIF extension is parsing EXIF information from an image, e.g. via exif_read_data() function, in PHP versions 7.2.x below 7.2.26, 7.3.x below 7.3.13 and 7.4.0 it is possible to supply it with data what will cause it to read past the allocated buffer. This may lead to information disclosure or crash.

In PHP versions 7.2.x below 7.2.26, 7.3.x below 7.3.13 and 7.4.0 on Windows, PHP link() function accepts filenames with embedded \0 byte and treats them as terminating at that byte. This could lead to security vulnerabilities, e.g. in applications checking paths that the code is allowed to access.

In PHP versions 7.2.x below 7.2.26, 7.3.x below 7.3.13 and 7.4.0, PHP bcmath extension functions on some systems, including Windows, can be tricked into reading beyond the allocated space by supplying it with string containing characters that are identified as numeric by the OS but aren't ASCII numbers. This can read to disclosure of the content of some memory locations.

In PHP versions 7.2.x below 7.2.26, 7.3.x below 7.3.13 and 7.4.0, PHP DirectoryIterator class accepts filenames with embedded \0 byte and treats them as terminating at that byte. This could lead to security vulnerabilities, e.g. in applications checking paths that the code is allowed to access.

When PHP EXIF extension is parsing EXIF information from an image, e.g. via exif_read_data() function, in PHP versions 7.2.x below 7.2.26, 7.3.x below 7.3.13 and 7.4.0 it is possible to supply it with data what will cause it to read past the allocated buffer. This may lead to information disclosure or crash.

Oniguruma through 6.9.3, as used in PHP 7.3.x and other products, has a heap-based buffer over-read in str_lower_case_match in regexec.c.

In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it is possible to cause FPM module to write past allocated buffers into the space reserved for FCGI protocol data, thus opening the possibility of remote code execution.