CVE-2024-56331

Uptime Kuma is an open source, self-hosted monitoring tool. An Improper URL Handling Vulnerability allows an attacker to access sensitive local files on the server by exploiting the file:/// protocol. This vulnerability is triggered via the "real-browser" request type, which takes a screenshot of the URL provided by the attacker. By supplying local file paths, such as file:///etc/passwd, an attacker can read sensitive data from the server. This vulnerability arises because the system does not properly validate or sanitize the user input for the URL field. Specifically: 1. The URL input (<input data-v-5f5c86d7="" id="url" type="url" class="form-control" pattern="https?://.+" required="">) allows users to input arbitrary file paths, including those using the file:/// protocol, without server-side validation. 2. The server then uses the user-provided URL to make a request, passing it to a browser instance that performs the "real-browser" request, which takes a screenshot o