Apprise forwards configured auth headers across cross-origin HTTP redirects
Apprise's HTTP-based notification plugins and its HTTP attachment / config loaders (apprise/attachment/http.py, apprise/config/http.py) follow HTTP 3xx redirects by default and re-send the user-configured auth headers and query parameters on the redirected request. If an operator-configured destination is later compromised (service takeover, malicious update), or an attacker holds a MITM position on an unprotected network path, that destination can return a 302 Location: to an arbitrary host and Apprise forwards the …