From b15f8b06425edbfc3a7cef2a55c609b12ee14377 Mon Sep 17 00:00:00 2001 From: Alex Gleason Date: Wed, 23 Aug 2023 13:10:19 -0500 Subject: Prevent webfinger spoofing --- lib/pleroma/web/web_finger.ex | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib') diff --git a/lib/pleroma/web/web_finger.ex b/lib/pleroma/web/web_finger.ex index 26fb8af84..a84a4351b 100644 --- a/lib/pleroma/web/web_finger.ex +++ b/lib/pleroma/web/web_finger.ex @@ -216,10 +216,26 @@ defmodule Pleroma.Web.WebFinger do _ -> {:error, {:content_type, nil}} end + |> case do + {:ok, data} -> validate_webfinger(address, data) + error -> error + end else error -> Logger.debug("Couldn't finger #{account}: #{inspect(error)}") error end end + + defp validate_webfinger(url, %{"subject" => "acct:" <> acct} = data) do + with %URI{host: request_host} <- URI.parse(url), + [_name, acct_host] <- String.split(acct, "@"), + {_, true} <- {:hosts_match, acct_host == request_host} do + {:ok, data} + else + _ -> {:error, {:webfinger_invalid, url, data}} + end + end + + defp validate_webfinger(url, data), do: {:error, {:webfinger_invalid, url, data}} end -- cgit v1.2.3