Zitadel before 4.16.2 SSRF via Organization Domain HTTP Verification

Zitadel before 4.16.2 contains a server-side request forgery vulnerability that allows attackers to make the server request internal resources through organization domain HTTP verification. The challenge fetch uses Go's default http.Get instead of the protected client, so attackers can register domains that redirect to loopback, internal, or cloud metadata addresses to scan ports and map internal networks.