CMSimple vulnerabilities

CMSimple 5.24 ships with CSRF protection disabled by default, which turns csrfProtection() into a no-op on every state-changing admin request, and it does not send the csrf_token hidden field in admin forms. Because administrator authentication is cookie-only and no CSRF token is enforced, an unauthenticated attacker can induce a logged-in administrator's browser to issue a forged content-save request with a text payload containing a scripting marker. The marker is stored verbatim into content/content.php; on every subsequent page view evaluate_cmsimple_scripting() (functions.php) executes the marker body with PHP eval() — for all visitors, including unauthenticated ones. This yields persistent remote code execution on the web server.

A code execution vulnerability exists in CMSimple 5.22 in the CoAuthors plugin. An authenticated low-privileged user who can modify page content and provide controlled imported content can trigger server-side execution by referencing crafted external or uploaded text content through the affected content import feature.

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.