9a499734c5
* Fix the RCE vuln via Upload from URL This commit attemps to fix the Remote Code Execution (authenticated) via Upload from URL. Some notes about the proposed solution: * A new function (fm_is_file_allowed) has been created to validate if the filename is allowed. This function gets the the filename as parameter and returns true if it validates as allowed. Otherwise returns false (the default). * It's better to have such validatation(s) in one place instead of spread all over the code. There are other places in the application where the filename is validated and they should all be refactored to call this function. Then we can focus all needed validations in one place only! NOTE: This refactoring was not done - the only goal was to fix this security vulnerability only. * The fm_is_file_allowed() function validates the filename based on its extension only. No other validatation(s) have been implemented in this commit. * File extensions are assumed to be case-insensitive. For example, php == PHP == Php == PhP, etc. This is consitent with some web servers. Without this, the user will have to populate the $allowed_extensions with all possible allowed combinations. * Although, there is one drawback to the current solution, which is that all files must have an extension to be uploaded. This is not consitent with modern filesystems. Maybe a better solution would be to automatically append an extension to the filename if no extension has been found (e.g., .html or .txt which are generally considered to be harmless). This must be decided by the application's maintainers. * Fix the RCE vulns via new/rename file Sanitize the arguments to stat using escapeshellarg() Co-authored-by: Jorge Morgado <jorge@morgado.ch>
156 KiB
156 KiB