10. How to bypass disable_functions in PHP, and what is the underlying principle?

PHP 7 UAF Vulnerability: This vulnerability exploits a heap overflow in the PHP garbage collector to bypass disable_functions and execute system commands.
PHP 7 Backtrace UAF: Used in the debug_backtrace() function. We can induce it to return a reference to a variable that has been destroyed, leading to a use-after-free vulnerability.
Json Serializer UAF: Exploits a heap overflow triggered in the JSON serialiser to bypass disable_functions and execute system commands.
Apache Mod CGI: When Apache is configured to enable CGI, the ScriptAlias directive can specify a directory where executable CGI programmes can be placed.
PHP-FPM/FastCGI:
PHP FFI: FFI (Foreign Function Interface) is a technology for calling code from another language. PHP’s FFI extension allows you to call C code within PHP.