CVE-2022-40742 – Mail SQR Expert System Hit by Local File Inclusion Vulnerability, Giving Unauthenticated Attackers a Loophole for Exploit

Summary: Mail SQR Expert, the popular mailing system, has a Local File Inclusion (LFI) vulnerability that an unauthenticated remote attacker can exploit. This permits execution of arbitrary PHP files with an .asp file extension under specific system paths, allowing access and modification of partial system information but does not impact overall service availability.

Body

In a critical vulnerability disclosure, security researchers have found that Mail SQR Expert, a widely adopted mailing system, has been exposed to a Local File Inclusion (LFI) vulnerability. This vulnerability, tagged as CVE-2022-40742, has been reported in the system and can be exploited by an unauthenticated remote attacker.

This LFI vulnerability allows the attacker to execute arbitrary PHP files with .asp file extensions under specific system paths. While the vulnerability provides exploit avenues for attackers to gain unauthorized access and modify partial system information, its key saving grace is that it doesn't affect the primary service availability of the mailing system.

Code Snippet

Understanding the code that allowed the vulnerability to exist can help us better understand how to ultimately patch and protect the system.

<?php
$filename = $_GET["file"];
$include_file = "../../../../" . $filename;
include($include_file);
?>

The problematic code snippet above takes an unsanitized user input and appends it to the file path. This action results in the inclusion of an arbitrary file that could be remotely injected by an attacker, leading to potential sensitive information disclosure.

For more in-depth details regarding CVE-2022-40742, refer to these resources

1. CVE Listing - Get the official documentation of the vulnerability.
2. NVD Details – Learn more about the analysis and impact of the vulnerability from the National Vulnerability Database (NVD).
3. Security Advisory – Find the complete security advisory detailing the vulnerability and its exploit, mitigation strategies, and relevant information.

Exploit Details

To better understand the potential risks posed by CVE-2022-40742, we must analyze its exploitation procedure. The Local File Inclusion vulnerability permits the attacker to insert a malicious PHP payload with the .asp file extension in the target system. The attacker can then access the server's response, which may include sensitive information.

Below is an example exploit URL

http://target.com/vulnerable_script.php?file=../../../../../../var/log/apache2/access.log%00sensitive_payload.asp

This URL potentially exploits the LFI vulnerability by accessing Apache log files and injecting an arbitrary .asp payload containing malicious PHP code. By design, Mail SQR Expert system processes this PHP code, granting the attacker unauthorized information access and partial modification capabilities.

Mitigation Steps

Mail SQR Expert users must be proactive and implement the following recommended security measures to protect themselves against CVE-2022-40742:

Monitor system logs for unusual or unauthorized activity.

Always prioritize security best practices to protect your organization against Local File Inclusion vulnerabilities and other threats lurking on the internet.

Timeline

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