In GetSimpleCMS 3.3.15, admin/upload.php blocks .html uploads but Internet Explorer render HTML elements in a .eml file, because of admin/upload-uploadify.php, and validate_safe_file in admin/inc/security_functions.php.
No PoCs from references.
- https://github.com/RajatSethi2001/FUSE
- https://github.com/WSP-LAB/FUSE