CVE-2022-3562: Cross-Site Scripting (XSS) Vulnerability in LibreNMS Prior to v22.10.

As an IT enthusiast or system administrator, it's important to be aware of any newly discovered vulnerabilities that may affect popular applications for which patches need to be applied. In this in-depth article, we are going to explore the CVE-2022-3562 vulnerability, a stored Cross-Site Scripting (XSS) exploit in the LibreNMS monitoring system that may put your data at risk. We'll look into the background of this vulnerability, the affected component, and how to fix the issue with the help of updated patches.

Background

LibreNMS is a widely used, open-source networking monitoring tool that provides a wealth of features in a user-friendly interface. However, like any software, it is not immune to security flaws. CVE-2022-3562, a stored Cross-Site Scripting (XSS) vulnerability, is one such flaw that was discovered in its GitHub repository before version 22.10.. It is crucial to understand these vulnerabilities and take appropriate action to avoid security breaches.

Details of the Vulnerability

The vulnerability is categorized as a stored XSS, which occurs when an attacker injects code into an application, and it persists in the database. When a victim user visits the app, the stored XSS code performs attacks by stealing the user's cookies, session information, or forcing the user to perform unwanted actions.

The specific flaw in LibreNMS is related to the device group name input field within the software, which allows users to create custom device groups for monitoring. By injecting malicious XSS code into the input field, the attacker can exploit this vulnerability.

Here is a code snippet of the input field that accepts user-supplied data

<label for="groupname">Group name</label>
<input type="text" name="groupname" id="groupname" maxlength="255" value="">

Original References

For more information about this vulnerability, you can refer to the CVE database and GitHub repository that discuss the issue and the associated fixes:

1. CVE Database: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-3562
2. GitHub repository: https://github.com/librenms/librenms/security/advisories/GHSA-p8jc-4w7j-vc99

How to Fix the Vulnerability

To fix this vulnerability, you need to update the LibreNMS software to the patched version (22.10. or later). Follow these steps to update your LibreNMS installation:

Connect to the server hosting LibreNMS through SSH.

2. Navigate to the LibreNMS install directory, typically located at /opt/librenms.

cd /opt/librenms

Run the following command to update LibreNMS to the latest version

./daily.sh

4. Verify that the update was successful by checking the LibreNMS version in its web interface or by running the following command:

./validate.php

5. If you have any custom device groups, validate that the group names do not contain any malicious code injections. To remove such injections, manually edit each device group name containing any suspicious characters or script tags.

6. Finally, it's recommended to educate users with access to LibreNMS about the dangers and prevention of XSS attacks.

Conclusion

By understanding the CVE-2022-3562 vulnerability and following the steps outlined in this article, you should be able to protect your LibreNMS installation from this stored Cross-Site Scripting (XSS) attack. Make regular updates to your software and stay informed about the latest security advisories to ensure the ongoing security and performance of your network monitoring system.

Timeline

Published on: 11/20/2022 05:15:00 UTC
Last modified on: 11/21/2022 13:19:00 UTC