In PHP versions 8.1 before 8.1.29, 8.2 before 8.2.20, 8.3 before 8.3.8, when using Apache and PHP-CGI on Windows, if the system is set up to use certain code pages, Windows may use "Best-Fit" behavior to replace characters in command line given to Win32 API functions. PHP CGI module may misinterpret those characters as PHP options, which may allow a malicious user to pass options to PHP binary being run, and thus reveal the source code of scripts or run arbitrary PHP code on the server. References: https://github.com/php/php-src/security/advisories/GHSA-3qgc-jrrr-25jv http://www.openwall.com/lists/oss-security/2024/06/07/1 https://arstechnica.com/security/2024/06/php-vulnerability-allows-attackers-to-run-malicious-code-on-windows-servers/ https://labs.watchtowr.com/no-way-php-strikes-again-cve-2024-4577/ https://blog.orange.tw/2024/06/cve-2024-4577-yet-another-php-rce.html https://cert.be/en/advisory/warning-php-remote-code-execution-patch-immediately https://devco.re/blog/2024/06/06/security-alert-cve-2024-4577-php-cgi-argument-injection-vulnerability-en/ PHP 8 ChangeLogs: https://www.php.net/ChangeLog-8.php#8.1.29 https://www.php.net/ChangeLog-8.php#8.2.20 https://www.php.net/ChangeLog-8.php#8.3.8