ThingsBoard versions < 4.2.1 contain a server-side request forgery (SSRF) vulnerability in the dashboards Image Upload Gallery feature. An attacker can upload a malicious SVG file that references a remote URL. If the server processes the SVG file in a way that parses external references, it may initiate unintended outbound requests. This can be used to access internal services or resources.
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.