From 4505bc1e587ce76683e21a41f90fb2956ed2a084 Mon Sep 17 00:00:00 2001
From: Mark Felder <feld@feld.me>
Date: Fri, 26 May 2023 13:23:59 -0400
Subject: [PATCH] Filter OEmbed HTML tags

---
 changelog.d/3891.fix                          | 1 +
 lib/pleroma/web/rich_media/parsers/o_embed.ex | 4 ++--
 test/pleroma/web/rich_media/parser_test.exs   | 4 ++--
 3 files changed, 5 insertions(+), 4 deletions(-)
 create mode 100644 changelog.d/3891.fix

diff --git a/changelog.d/3891.fix b/changelog.d/3891.fix
new file mode 100644
index 000000000..f1fb62d82
--- /dev/null
+++ b/changelog.d/3891.fix
@@ -0,0 +1 @@
+OEmbed HTML tags are now filtered
diff --git a/lib/pleroma/web/rich_media/parsers/o_embed.ex b/lib/pleroma/web/rich_media/parsers/o_embed.ex
index 75318d9c7..0f303176c 100644
--- a/lib/pleroma/web/rich_media/parsers/o_embed.ex
+++ b/lib/pleroma/web/rich_media/parsers/o_embed.ex
@@ -6,8 +6,8 @@ defmodule Pleroma.Web.RichMedia.Parsers.OEmbed do
   def parse(html, _data) do
     with elements = [_ | _] <- get_discovery_data(html),
          oembed_url when is_binary(oembed_url) <- get_oembed_url(elements),
-         {:ok, oembed_data} <- get_oembed_data(oembed_url) do
-      oembed_data
+         {:ok, oembed_data = %{"html" => html}} <- get_oembed_data(oembed_url) do
+      %{oembed_data | "html" => Pleroma.HTML.filter_tags(html)}
     else
       _e -> %{}
     end
diff --git a/test/pleroma/web/rich_media/parser_test.exs b/test/pleroma/web/rich_media/parser_test.exs
index ffdc4e5d7..9064138a6 100644
--- a/test/pleroma/web/rich_media/parser_test.exs
+++ b/test/pleroma/web/rich_media/parser_test.exs
@@ -129,7 +129,7 @@ defmodule Pleroma.Web.RichMedia.ParserTest do
               }}
   end
 
-  test "parses OEmbed" do
+  test "parses OEmbed and filters HTML tags" do
     assert Parser.parse("http://example.com/oembed") ==
              {:ok,
               %{
@@ -139,7 +139,7 @@ defmodule Pleroma.Web.RichMedia.ParserTest do
                 "flickr_type" => "photo",
                 "height" => "768",
                 "html" =>
-                  "<a data-flickr-embed=\"true\" href=\"https://www.flickr.com/photos/bees/2362225867/\" title=\"Bacon Lollys by \u202E\u202D\u202Cbees\u202C, on Flickr\"><img src=\"https://farm4.staticflickr.com/3040/2362225867_4a87ab8baf_b.jpg\" width=\"1024\" height=\"768\" alt=\"Bacon Lollys\"></a><script async src=\"https://embedr.flickr.com/assets/client-code.js\" charset=\"utf-8\"></script>",
+                  "<a href=\"https://www.flickr.com/photos/bees/2362225867/\" title=\"Bacon Lollys by \u202E\u202D\u202Cbees\u202C, on Flickr\"><img src=\"https://farm4.staticflickr.com/3040/2362225867_4a87ab8baf_b.jpg\" width=\"1024\" height=\"768\" alt=\"Bacon Lollys\"/></a>",
                 "license" => "All Rights Reserved",
                 "license_id" => 0,
                 "provider_name" => "Flickr",