External server-side request vulnerability in MESbook 20221021.03 version, which could allow a remote, unauthenticated attacker to exploit the endpoint /api/Proxy/Post?userName=&password=&uri=<FILE|INTERNAL URL|IP/HOST or /api/Proxy/Get?userName=&password=&uri=<ARCHIVO|URL INTERNA|IP/HOST to read the source code of web files, read internal files or access network 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.