Pheditor is a single-file editor and file manager written in PHP. From version 2.0.1 to before version 2.0.4, an OS Command Injection vulnerability in the terminal action handler allows any authenticated user to execute arbitrary OS commands by injecting shell metacharacters into the 'dir' POST parameter, completely bypassing the TERMINAL_COMMANDS whitelist and achieving full Remote Code Execution with web server privileges. This issue has been patched in version 2.0.4.