User Manager: Blocked Extensions Settings

The Blocked Extensions feature allows administrators to define a list of file extensions that users are prevented from uploading or renaming files to on the server, or a list of extensions that are the only types of files that can be uploaded and all other extensions are blocked. The Blocked Extensions feature enhances the security of your FTP server by preventing the upload of potentially harmful or unwanted file types.

Steps to manage extensions:

1. Navigate to Blocked Extensions:
   • In the left-hand navigation menu of the Cerberus FTP Server administration console, navigate to User Manager, then within the User Manager interface, locate the tabs at the top.
   • Click on the Blocked Extensions tab.
     
     Blocked Extensions page in User Manager
2. Understanding the Interface:
   • Deny / Allow Buttons:
     • Deny (Selected/Highlighted on the screenshot): This indicates that the system is currently in "Deny" mode, meaning the listed extensions are blocked. This is the default and intended functionality for blocking extensions.
     • Allow (Unselected): If this button were selected, the system would operate in "Allow" mode, meaning only the listed extensions would be permitted for upload and rename.
   • Blocked Extensions List: This section displays the currently blocked file extensions. In the example image above, the following extensions are blocked: exe* (The optional asterisk acts as a wildcard, blocking any extension starting with "exe"), svg and xml
   • List Controls:
     • Show [Number]: Allows you to select the number of blocked extensions displayed per page (e.g., 10, 25, 50).
     • Filter: Allows you to search for specific extensions within the list.
     • Navigation Buttons (First, [number(s)], Last): Used to navigate between multiple pages of blocked extensions if the list exceeds the displayed number.
3. Adding New Blocked Extensions:
   • In the Add A New Extension Or List Of Extensions section, in the Extension field, type the file extension you want to block. There is no need to include a dot before the extension.
     To block multiple extensions at once, enter them in the Extension field separated by commas. For example, to block executables, batch files, and PHP scripts, enter exe,bat,php.
   • Click the Add button. The newly added extension(s) will appear in the Blocked Extensions list.
4. Removing Blocked Extensions:
   • If you wish to remove an extension from the list:
     • Click on an extension and then click the trash can/bin icon to delete.
     • You can select multiple extensions, or use the checkbox/tick box icon to select all extensions and  then click the trash can/bin icon to delete.