Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. In versions 4.2.0 through 7.5.3, and 8.0.0 through 8.3.1-alpha.1, there is a Server-Side Request Forgery (SSRF) vulnerability in the file upload functionality when trying to upload a Parse.File with uri parameter, allowing execution of an arbitrary URI. The vulnerability stems from a file upload feature in which Parse Server retrieves the file data from a URI that is provided in the request. A request to the provided URI is executed, but the response is not stored in Parse Servers file storage as the server crashes upon receiving the response. This issue is fixed in versions 7.5.4 and 8.4.0-alpha.1.
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.