In PHP versions 7.2.x below 7.2.31, 7.3.x below 7.3.18 and 7.4.x below 7.4.6, when HTTP file uploads are allowed, supplying overly long filenames or field names could lead PHP engine to try to allocate oversized memory storage, hit the memory limit and stop processing the request, without cleaning up temporary files created by upload request. This potentially could lead to accumulation of uncleaned temporary files exhausting the disk space on the target server.
In PHP versions 7.2.x below 7.2.30, 7.3.x below 7.3.17 and 7.4.x below 7.4.5, if PHP is compiled with EBCDIC support (uncommon), urldecode() function can be made to access locations past the allocated memory, due to erroneously using signed numbers as array indexes.
In PHP versions 7.2.x below 7.2.29, 7.3.x below 7.3.16 and 7.4.x below 7.4.4, while using get_headers() with user-supplied URL, if the URL contains zero (\0) character, the URL will be silently truncated at it. This may cause some software to make incorrect assumptions about the target of the get_headers() and possibly send some information to a wrong server.
In PHP versions 7.2.x below 7.2.9, 7.3.x below 7.3.16 and 7.4.x below 7.4.4, while parsing EXIF data with exif_read_data() function, it is possible for malicious data to cause PHP to read one byte of uninitialized memory. This could potentially lead to information disclosure or crash.
In PHP versions 7.2.x below 7.2.28, 7.3.x below 7.3.15 and 7.4.x below 7.4.3, when using file upload functionality, if upload progress tracking is enabled, but session.upload_progress.cleanup is set to 0 (disabled), and the file upload fails, the upload procedure would try to clean up data that does not exist and encounter null pointer dereference, which would likely lead to a crash.
In PHP versions 7.2.x below 7.2.28, 7.3.x below 7.3.15 and 7.4.x below 7.4.3, when creating PHAR archive using PharData::buildFromIterator() function, the files are added with default permissions (0666, or all access) even if the original files on the filesystem were with more restrictive permissions. This may result in files having more lax permissions than intended when such archive is extracted.
In PHP versions 7.3.x below 7.3.15 and 7.4.x below 7.4.3, while extracting PHAR files on Windows using phar extension, certain content inside PHAR file could lead to one-byte read past the allocated buffer. This could potentially lead to information disclosure or crash.
When using fgetss() function to read data with stripping tags, in PHP versions 7.2.x below 7.2.27, 7.3.x below 7.3.14 and 7.4.x below 7.4.2 it is possible to supply data that will cause this function to read past the allocated buffer. This may lead to information disclosure or crash.
When using certain mbstring functions to convert multibyte encodings, in PHP versions 7.2.x below 7.2.27, 7.3.x below 7.3.14 and 7.4.x below 7.4.2 it is possible to supply data that will cause function mbfl_filt_conv_big5_wchar 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, 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.