CVE-2020-20918: 
Pluck CMS vulnerability analysis and mitigation

CVE-2020-20918 is a security vulnerability discovered in Pluck CMS version 4.7.10-dev2. The vulnerability allows remote attackers to execute arbitrary PHP code via the hidden parameter to admin.php when editing a page. The issue was disclosed through a GitHub issue report (GitHub Issue).

The vulnerability exists in the data/inc/functions.admin.php file (lines 531-535). The application saves the hidden parameter passed by the POST request to PHP but fails to properly escape special characters (like single quotes) in the value. This allows attackers to break out of the PHP syntax and execute arbitrary commands like phpinfo() or eval() functions (GitHub Issue).

If successfully exploited, this vulnerability allows authenticated attackers to execute arbitrary PHP code on the server. This could lead to complete system compromise, including the ability to read sensitive files, modify website content, or use the server for further attacks (GitHub Issue).

Users should upgrade to a version newer than Pluck CMS 4.7.10-dev2 that contains the security fix. If upgrading is not immediately possible, administrators should implement strict input validation for the hidden parameter and ensure proper escaping of special characters in user inputs (GitHub Issue).