CVE-2025-27920: Directory Traversal Vulnerability in Output Messenger

Overview

The Common Vulnerabilities and Exposures (CVE) system has identified a critical vulnerability in Output Messenger, a popular communication tool used by many businesses. This vulnerability, tagged as CVE-2025-27920, could potentially allow attackers to access sensitive files outside the intended directory. The vulnerability occurs due to the application’s improper handling of file paths, leading to a possible directory traversal attack. Its criticality is underlined by the CVSS Severity Score of 9.8, which underscores the potential for severe damage and data leakage.

Vulnerability Summary

CVE ID: CVE-2025-27920
Severity: Critical (CVSS: 9.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise and data leakage

Affected Products

Product | Affected Versions

Output Messenger | Versions before 2.0.63

How the Exploit Works

The exploit takes advantage of improper file path handling within Output Messenger. By using ‘../’ sequences in parameters, attackers can manipulate the file path to access directories and files outside of the intended scope. This directory traversal allows them to potentially access sensitive files, configurations, and data that would otherwise be off-limits.

Conceptual Example Code

Here’s a conceptual example of how this vulnerability might be exploited. This example simulates a malicious HTTP request, utilizing directory traversal to access a sensitive configuration file.

GET /download.php?file=../../../../etc/passwd HTTP/1.1
Host: vulnerablemessenger.example.com

In this example, the “../” sequence is used to move up in the directory structure. As a result, instead of accessing a file within the intended directory, the attacker could potentially access and download the ‘/etc/passwd’ file, a sensitive file containing user account information on a Unix-based system.

Mitigation Guidance

To mitigate this vulnerability, users of Output Messenger are urged to update their software to version 2.0.63 or later, where the vulnerability has been patched. If immediate update isn’t possible, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure, providing some level of protection against potential attacks exploiting this vulnerability.