Cross-site scripting (XSS) vulnerability in whizzywig/wb.php in CMSimple Classic 3.54 and earlier, possibly as downloaded before February 26, 2014, allows remote attackers to inject arbitrary web script or HTML via the d parameter.

CMSimple 4.7.5 has XSS via an admin's use of a ?file=config&action=array URI.

CMSimple 4.7.5 has XSS via an admin's upload of an SVG file at a ?userfiles&subdir=userfiles/images/flags/ URI.

CMSimple 5.4 is vulnerable to Directory Traversal. The vulnerability exists when a user changes the file name to malicious file on config.php leading to remote code execution.

CMSimple 5.4 is vulnerable to Cross Site Scripting (XSS) via the file upload feature.

CMSimple 5.2 contains a stored cross-site scripting vulnerability in the Filebrowser External input field that allows attackers to inject malicious JavaScript. Attackers can place unfiltered JavaScript code that executes when users click on Page or Files tabs, enabling persistent script injection.

CMSimple 5.4 contains a cross-site scripting vulnerability that allows attackers to bypass input filtering by using HTML to Unicode encoding. Attackers can inject malicious scripts by encoding payloads like ')-alert(1)// and execute arbitrary JavaScript when victims interact with delete buttons.

CMSimple 5.4 contains an authenticated local file inclusion vulnerability that allows remote attackers to manipulate PHP session files and execute arbitrary code. Attackers can leverage the vulnerability by changing the functions file path and uploading malicious PHP code through session file upload mechanisms.

CMSimple 5.4 contains an authenticated remote code execution vulnerability that allows logged-in attackers to inject malicious PHP code into template files. Attackers can exploit the template editing functionality by crafting a reverse shell payload and saving it through the template editing endpoint with a valid CSRF token.

CMSimple 5.15 contains a remote command execution vulnerability that allows authenticated attackers to modify file extensions and upload malicious PHP files. Attackers can append ',php' to Extensions_userfiles and upload a shell script to the media directory to execute arbitrary code on the server.