commit: 535a5ecad04c9c49105a77e7025fe9f4b4d23ba6
parent 1f4be2b3495b6df03843f923a53aff5913e1ef0d
Author: Mint <mint@plagu.ee>
Date: Sat, 2 Sep 2023 01:43:25 +0300
CommonAPI: Prevent users from accessing media of other users
commit 1afde067b12ad0062c1820091ea9b0a680819281 upstream.
Diffstat:
9 files changed, 85 insertions(+), 30 deletions(-)
diff --git a/changelog.d/check-attachment-attribution.security b/changelog.d/check-attachment-attribution.security
@@ -0,0 +1 @@
+CommonAPI: Prevent users from accessing media of other users by creating a status with reused attachment ID
diff --git a/lib/pleroma/scheduled_activity.ex b/lib/pleroma/scheduled_activity.ex
@@ -40,7 +40,11 @@ defmodule Pleroma.ScheduledActivity do
%{changes: %{params: %{"media_ids" => media_ids} = params}} = changeset
)
when is_list(media_ids) do
- media_attachments = Utils.attachments_from_ids(%{media_ids: media_ids})
+ media_attachments =
+ Utils.attachments_from_ids(
+ %{media_ids: media_ids},
+ User.get_cached_by_id(changeset.data.user_id)
+ )
params =
params
diff --git a/lib/pleroma/web/common_api.ex b/lib/pleroma/web/common_api.ex
@@ -33,6 +33,7 @@ defmodule Pleroma.Web.CommonAPI do
def post_chat_message(%User{} = user, %User{} = recipient, content, opts \\ []) do
with maybe_attachment <- opts[:media_id] && Object.get_by_id(opts[:media_id]),
+ :ok <- validate_chat_attachment_attribution(maybe_attachment, user),
:ok <- validate_chat_content_length(content, !!maybe_attachment),
{_, {:ok, chat_message_data, _meta}} <-
{:build_object,
@@ -71,6 +72,17 @@ defmodule Pleroma.Web.CommonAPI do
text
end
+ defp validate_chat_attachment_attribution(nil, _), do: :ok
+
+ defp validate_chat_attachment_attribution(attachment, user) do
+ with :ok <- Object.authorize_access(attachment, user) do
+ :ok
+ else
+ e ->
+ e
+ end
+ end
+
defp validate_chat_content_length(_, true), do: :ok
defp validate_chat_content_length(nil, false), do: {:error, :no_content}
diff --git a/lib/pleroma/web/common_api/activity_draft.ex b/lib/pleroma/web/common_api/activity_draft.ex
@@ -111,7 +111,7 @@ defmodule Pleroma.Web.CommonAPI.ActivityDraft do
end
defp attachments(%{params: params} = draft) do
- attachments = Utils.attachments_from_ids(params)
+ attachments = Utils.attachments_from_ids(params, draft.user)
draft = %__MODULE__{draft | attachments: attachments}
case Utils.validate_attachments_count(attachments) do
diff --git a/lib/pleroma/web/common_api/utils.ex b/lib/pleroma/web/common_api/utils.ex
@@ -23,21 +23,21 @@ defmodule Pleroma.Web.CommonAPI.Utils do
require Logger
require Pleroma.Constants
- def attachments_from_ids(%{media_ids: ids, descriptions: desc}) do
- attachments_from_ids_descs(ids, desc)
+ def attachments_from_ids(%{media_ids: ids, descriptions: desc}, user) do
+ attachments_from_ids_descs(ids, desc, user)
end
- def attachments_from_ids(%{media_ids: ids}) do
- attachments_from_ids_no_descs(ids)
+ def attachments_from_ids(%{media_ids: ids}, user) do
+ attachments_from_ids_no_descs(ids, user)
end
- def attachments_from_ids(_), do: []
+ def attachments_from_ids(_, _), do: []
- def attachments_from_ids_no_descs([]), do: []
+ def attachments_from_ids_no_descs([], _), do: []
- def attachments_from_ids_no_descs(ids) do
+ def attachments_from_ids_no_descs(ids, user) do
Enum.map(ids, fn media_id ->
- case get_attachment(media_id) do
+ case get_attachment(media_id, user) do
%Object{data: data} -> data
_ -> nil
end
@@ -45,21 +45,26 @@ defmodule Pleroma.Web.CommonAPI.Utils do
|> Enum.reject(&is_nil/1)
end
- def attachments_from_ids_descs([], _), do: []
+ def attachments_from_ids_descs([], _, _), do: []
- def attachments_from_ids_descs(ids, descs_str) do
+ def attachments_from_ids_descs(ids, descs_str, user) do
{_, descs} = Jason.decode(descs_str)
Enum.map(ids, fn media_id ->
- with %Object{data: data} <- get_attachment(media_id) do
+ with %Object{data: data} <- get_attachment(media_id, user) do
Map.put(data, "name", descs[media_id])
end
end)
|> Enum.reject(&is_nil/1)
end
- defp get_attachment(media_id) do
- Repo.get(Object, media_id)
+ defp get_attachment(media_id, user) do
+ with %Object{data: _data} = object <- Repo.get(Object, media_id),
+ :ok <- Object.authorize_access(object, user) do
+ object
+ else
+ _ -> nil
+ end
end
@spec get_to_and_cc(ActivityDraft.t()) :: {list(String.t()), list(String.t())}
diff --git a/test/pleroma/web/common_api/utils_test.exs b/test/pleroma/web/common_api/utils_test.exs
@@ -586,41 +586,56 @@ defmodule Pleroma.Web.CommonAPI.UtilsTest do
end
end
- describe "attachments_from_ids_descs/2" do
+ describe "attachments_from_ids_descs/3" do
test "returns [] when attachment ids is empty" do
- assert Utils.attachments_from_ids_descs([], "{}") == []
+ assert Utils.attachments_from_ids_descs([], "{}", nil) == []
end
test "returns list attachments with desc" do
- object = insert(:note)
+ user = insert(:user)
+ object = insert(:note, %{user: user})
desc = Jason.encode!(%{object.id => "test-desc"})
- assert Utils.attachments_from_ids_descs(["#{object.id}", "34"], desc) == [
+ assert Utils.attachments_from_ids_descs(["#{object.id}", "34"], desc, user) == [
Map.merge(object.data, %{"name" => "test-desc"})
]
end
end
- describe "attachments_from_ids/1" do
+ describe "attachments_from_ids/2" do
test "returns attachments with descs" do
- object = insert(:note)
+ user = insert(:user)
+ object = insert(:note, %{user: user})
desc = Jason.encode!(%{object.id => "test-desc"})
- assert Utils.attachments_from_ids(%{
- media_ids: ["#{object.id}"],
- descriptions: desc
- }) == [
+ assert Utils.attachments_from_ids(
+ %{
+ media_ids: ["#{object.id}"],
+ descriptions: desc
+ },
+ user
+ ) == [
Map.merge(object.data, %{"name" => "test-desc"})
]
end
test "returns attachments without descs" do
- object = insert(:note)
- assert Utils.attachments_from_ids(%{media_ids: ["#{object.id}"]}) == [object.data]
+ user = insert(:user)
+ object = insert(:note, %{user: user})
+ assert Utils.attachments_from_ids(%{media_ids: ["#{object.id}"]}, user) == [object.data]
end
test "returns [] when not pass media_ids" do
- assert Utils.attachments_from_ids(%{}) == []
+ assert Utils.attachments_from_ids(%{}, nil) == []
+ end
+
+ test "returns [] when media_ids not belong to current user" do
+ user = insert(:user)
+ user2 = insert(:user)
+
+ object = insert(:attachment, %{user: user})
+
+ assert Utils.attachments_from_ids(%{media_ids: ["#{object.id}"]}, user2) == []
end
end
diff --git a/test/pleroma/web/common_api_test.exs b/test/pleroma/web/common_api_test.exs
@@ -279,6 +279,24 @@ defmodule Pleroma.Web.CommonAPITest do
assert {:reject, "[KeywordPolicy] Matches with rejected keyword"} ==
CommonAPI.post_chat_message(author, recipient, "GNO/Linux")
end
+
+ test "it reject messages with attachments not belonging to user" do
+ author = insert(:user)
+ not_author = insert(:user)
+ recipient = author
+
+ attachment = insert(:attachment, %{user: not_author})
+
+ {:error, message} =
+ CommonAPI.post_chat_message(
+ author,
+ recipient,
+ "123",
+ media_id: attachment.id
+ )
+
+ assert message == :forbidden
+ end
end
describe "unblocking" do
diff --git a/test/pleroma/web/mastodon_api/views/scheduled_activity_view_test.exs b/test/pleroma/web/mastodon_api/views/scheduled_activity_view_test.exs
@@ -48,7 +48,7 @@ defmodule Pleroma.Web.MastodonAPI.ScheduledActivityViewTest do
id: to_string(scheduled_activity.id),
media_attachments:
%{media_ids: [upload.id]}
- |> Utils.attachments_from_ids()
+ |> Utils.attachments_from_ids(user)
|> Enum.map(&StatusView.render("attachment.json", %{attachment: &1})),
params: %{
in_reply_to_id: to_string(activity.id),
diff --git a/test/pleroma/web/pleroma_api/views/chat_message_reference_view_test.exs b/test/pleroma/web/pleroma_api/views/chat_message_reference_view_test.exs
@@ -24,7 +24,7 @@ defmodule Pleroma.Web.PleromaAPI.ChatMessageReferenceViewTest do
filename: "an_image.jpg"
}
- {:ok, upload} = ActivityPub.upload(file, actor: user.ap_id)
+ {:ok, upload} = ActivityPub.upload(file, actor: recipient.ap_id)
{:ok, activity} =
CommonAPI.post_chat_message(user, recipient, "kippis :firefox:", idempotency_key: "123")
