GHSA-v7w9-63xh-6r3w LibreNMS has a Reflected XSS ('Cross-site Scripting') in librenms/includes/functions.php

• Packagist librenms/librenms: < 24.10.0 → fixed in 24.10.0

Summary A Reflected Cross-Site Scripting (XSS) vulnerability in the "section" parameter of the "logs" tab of a device allows attackers to inject arbitrary JavaScript. This vulnerability results in the execution of malicious code when a user accesses the page with a malicious "section" parameter, potentially compromising their session and enabling unauthorized actions. The issue arises from a lack of sanitization in the "report_this()" function. Details The "section" parameter of the "logs" tab is vulnerable to reflected XSS. An attacker can inject the following XSS payload into the "section" parameter: ```constructor'constructor')();``` When the page is loaded with this malicious parameter, the script executes immediately. This vulnerability occurs due to the lack of sanitization in the "report_this()" function. Other endpoints using this same function may also be vulnerable. The vulnerable sink is located here: https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/includes/functions.php#L523 https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/includes/html/pages/device/logs.inc.php#L93 PoC 1. Inject the following payload into the "section" parameter of the "logs" tab: ```constructor'constructor')();``` 2. Access the page with the injected payload. 3. Observe that the injected script executes when the page is loaded. Example URL: ```http:///device/device=1/tab=logs/section=%3Cscript%3Econstructor'constructor')();%3C%2fscript%3E/``` Example Request: ```http GET /device/device=1/tab=logs/section=%3Cscript%3Econstructor'constructor')();%3C%2fscript%3E/ HTTP/1.1 Host: Cookie: ``` Impact This vulnerability allows attackers to execute arbitrary JavaScript in the context of a user’s session by crafting a malicious URL. The attack could lead to session hijacking, unauthorized actions, or further exploitation by injecting malicious scripts.