Describe CVE-2017-16798.
What is CVE-2017-16798?
In CMS Made Simple 2.2.3.1, the is_file_acceptable function in modules/FileManager/action.upload.php only blocks file extensions that begin or end with a "php" substring, which allows remote attackers to bypass intended access restrictions or trigger XSS via other extensions, as demonstrated by .phtml, .pht, .html, or .svg..