CVE-2024-34470

The remediation process for the path traversal vulnerability (CVE-2024-34470) in HSC Mailinspector versions 5.2.17-3 through 5.2.18 involves implementing a patch to correct the improper filtering of the file and directory paths. This vulnerability resides in the /public/loader.php file, where the path parameter does not adequately filter whether the file and directory passed are part of the webroot. This flaw allows an attacker to read arbitrary files on the server.

To begin the remediation process, first, ensure that you have a backup of your current system state. This is a crucial step as it allows you to restore your system to its previous state in case of any unexpected issues during the remediation process.

Next, you need to access the server hosting the HSC Mailinspector application. This can be done using SSH (Secure Shell). The command to access the server via SSH is ssh user@your_server_ip. Replace user with your username and your_server_ip with the IP address of your server.

Once you have accessed the server, navigate to the directory containing the /public/loader.php file. The command to change directories in a Linux-based system is cd /path/to/directory. Replace /path/to/directory with the actual path to the directory containing the /public/loader.php file.

Open the /public/loader.php file in a text editor. If you're using a Linux-based system, you can use the nano text editor. The command to open the file in nano is nano /public/loader.php.

In the /public/loader.php file, locate the section of code that handles the path parameter. Implement a filter that checks if the file and directory passed are part of the webroot. This can be achieved by using the realpath() and strpos() functions in PHP. The realpath() function returns the absolute path of a file, and the strpos() function checks if a string is found within another string.

The code to implement the filter is as follows:

$path = $_GET['path'];
$realpath = realpath($path);
if (strpos($realpath, $_SERVER['DOCUMENT_ROOT']) !== 0) {
    die('Invalid path');
}

This code checks if the real path of the file or directory starts with the webroot path. If it doesn't, it stops the script execution and returns an 'Invalid path' message.

After implementing the patch, save and close the /public/loader.php file. If you're using the nano text editor, you can save and close the file by pressing Ctrl+X, then Y, then Enter.

Finally, restart the HSC Mailinspector application to apply the changes. The command to restart the application depends on how it's set up on your server. If it's set up as a service, you can use the service command followed by the service name and restart. For example, if the service name is mailinspector, the command is service mailinspector restart.

By following these steps, you should have successfully remediated the path traversal vulnerability in HSC Mailinspector.