The vulnerability is a critical OS Command Injection located in the XML::decodeP7M function in src/Util/XML.php. The function fails to sanitize the $file parameter before incorporating it into a command string that is executed via PHP's exec() function. An authenticated attacker can exploit this by uploading a ZIP archive containing a file with a malicious name (e.g., invoice.p7m";touch /tmp/pwned;echo ".p7m). When the application processes this file, the injected command is executed with the privileges of the web server. The analysis of the advisory identified two primary entry points that lead to the vulnerable function being called with user-controlled input. One is a loop in plugins/importFE_ZIP/actions.php that processes files from an uploaded ZIP. The other is the constructor of the FatturaElettronica class (plugins/importFE/src/FatturaElettronica.php), which also processes user-supplied filenames. Both XML::decodeP7M and FatturaElettronica::__construct would appear in a runtime profile during exploitation.