GetSimple CMS v3.3.16 was discovered to contain a remote code execution (RCE) vulnerability via the edited_file parameter in admin/theme-edit.php.

GetSimple CMS 3.3.16 allows in parameter 'permalink' on the Settings page persistent Cross Site Scripting which is executed when you create and open a new page

A Reflected Cross-Site Scripting (XSS) vulnerability in GetSimple CMS v3.3.16, in the admin/index.php login portal webpage, allows remote attackers to execute JavaScript code in the client's browser and harvest login credentials after a client clicks a link, enters credentials, and submits the login form.

GetSimple CMS v3.3.15 has Persistent Cross-Site Scripting (XSS) in admin/theme-edit.php.

There is Stored XSS in GetSimple CMS 3.3.12 via the admin/edit.php "post-menu" parameter, a related issue to CVE-2018-16325.

In GetSimpleCMS 3.3.15, admin/upload.php blocks .html uploads but there are several alternative cases in which HTML can be executed, such as a file with no extension or an unrecognized extension (e.g., the test or test.asdf filename), because of admin/upload-uploadify.php, and validate_safe_file in admin/inc/security_functions.php.

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.

An issue was discovered in GetSimple CMS 3.3.15. An administrator can insert stored XSS via the admin/settings.php Custom Permalink Structure parameter, which injects the XSS payload into any page created at the admin/pages.php URI.

An issue was discovered in GetSimple CMS v3.3.13. There is a CSRF vulnerability that can change the administrator's password via admin/settings.php. NOTE: The vendor reported that the PoC was sending a value for the nonce parameter

GetSimple CMS 3.3.14 has XSS via the admin/edit.php "Add New Page" field.