1 diff --git a/CHANGELOG.md b/CHANGELOG.md
2 index 9d9aadc6e8a0162d8944622f783a6301fefd6cfa..32ec440de55b707d01be37e21f1517542c9cf7d9 100644
5 @@ -14,7 +14,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
13 +- Prevent users from accessing media of other users by creating a status with reused attachment ID
18 - Fix XML External Entity (XXE) loading vulnerability allowing to fetch arbitary files from the server's filesystem
19 diff --git a/changelog.d/check-attachment-attribution.security b/changelog.d/check-attachment-attribution.security
21 index 0000000000000000000000000000000000000000..e0e46525b38d15e58423debbf9d799e85276d0ca
23 +++ b/changelog.d/check-attachment-attribution.security
25 +CommonAPI: Prevent users from accessing media of other users by creating a status with reused attachment ID
26 diff --git a/lib/pleroma/scheduled_activity.ex b/lib/pleroma/scheduled_activity.ex
27 index a7be585123d4be67e7513626b07c2e33c8b18388..0ed51ad07d43c0cc434e532852ce6a7ec1089d10 100644
28 --- a/lib/pleroma/scheduled_activity.ex
29 +++ b/lib/pleroma/scheduled_activity.ex
30 @@ -40,7 +40,11 @@ defp with_media_attachments(
31 %{changes: %{params: %{"media_ids" => media_ids} = params}} = changeset
33 when is_list(media_ids) do
34 - media_attachments = Utils.attachments_from_ids(%{media_ids: media_ids})
36 + Utils.attachments_from_ids(
37 + %{media_ids: media_ids},
38 + User.get_cached_by_id(changeset.data.user_id)
43 diff --git a/lib/pleroma/web/common_api.ex b/lib/pleroma/web/common_api.ex
44 index 89cc0d6fe82acfd418e8e5928bc4b44d72b17f79..44eb00075ee694005241c1eabfbb846e4668d665 100644
45 --- a/lib/pleroma/web/common_api.ex
46 +++ b/lib/pleroma/web/common_api.ex
47 @@ -33,6 +33,7 @@ def block(blocker, blocked) do
49 def post_chat_message(%User{} = user, %User{} = recipient, content, opts \\ []) do
50 with maybe_attachment <- opts[:media_id] && Object.get_by_id(opts[:media_id]),
51 + :ok <- validate_chat_attachment_attribution(maybe_attachment, user),
52 :ok <- validate_chat_content_length(content, !!maybe_attachment),
53 {_, {:ok, chat_message_data, _meta}} <-
55 @@ -71,6 +72,17 @@ defp format_chat_content(content) do
59 + defp validate_chat_attachment_attribution(nil, _), do: :ok
61 + defp validate_chat_attachment_attribution(attachment, user) do
62 + with :ok <- Object.authorize_access(attachment, user) do
70 defp validate_chat_content_length(_, true), do: :ok
71 defp validate_chat_content_length(nil, false), do: {:error, :no_content}
73 diff --git a/lib/pleroma/web/common_api/activity_draft.ex b/lib/pleroma/web/common_api/activity_draft.ex
74 index 9af635da8abafb9d9a4c1b59c00cc63261955d48..63ed48a27bbd4a4f2fdfd97776acadcf0fa72c74 100644
75 --- a/lib/pleroma/web/common_api/activity_draft.ex
76 +++ b/lib/pleroma/web/common_api/activity_draft.ex
77 @@ -111,7 +111,7 @@ defp full_payload(%{status: status, summary: summary} = draft) do
80 defp attachments(%{params: params} = draft) do
81 - attachments = Utils.attachments_from_ids(params)
82 + attachments = Utils.attachments_from_ids(params, draft.user)
83 draft = %__MODULE__{draft | attachments: attachments}
85 case Utils.validate_attachments_count(attachments) do
86 diff --git a/lib/pleroma/web/common_api/utils.ex b/lib/pleroma/web/common_api/utils.ex
87 index ff0814329583726d43ad52e6082662aee1212b45..6410815ea89153a65f20bacc24a5a5aed82a1aa0 100644
88 --- a/lib/pleroma/web/common_api/utils.ex
89 +++ b/lib/pleroma/web/common_api/utils.ex
90 @@ -23,21 +23,21 @@ defmodule Pleroma.Web.CommonAPI.Utils do
92 require Pleroma.Constants
94 - def attachments_from_ids(%{media_ids: ids, descriptions: desc}) do
95 - attachments_from_ids_descs(ids, desc)
96 + def attachments_from_ids(%{media_ids: ids, descriptions: desc}, user) do
97 + attachments_from_ids_descs(ids, desc, user)
100 - def attachments_from_ids(%{media_ids: ids}) do
101 - attachments_from_ids_no_descs(ids)
102 + def attachments_from_ids(%{media_ids: ids}, user) do
103 + attachments_from_ids_no_descs(ids, user)
106 - def attachments_from_ids(_), do: []
107 + def attachments_from_ids(_, _), do: []
109 - def attachments_from_ids_no_descs([]), do: []
110 + def attachments_from_ids_no_descs([], _), do: []
112 - def attachments_from_ids_no_descs(ids) do
113 + def attachments_from_ids_no_descs(ids, user) do
114 Enum.map(ids, fn media_id ->
115 - case get_attachment(media_id) do
116 + case get_attachment(media_id, user) do
117 %Object{data: data} -> data
120 @@ -45,21 +45,26 @@ def attachments_from_ids_no_descs(ids) do
121 |> Enum.reject(&is_nil/1)
124 - def attachments_from_ids_descs([], _), do: []
125 + def attachments_from_ids_descs([], _, _), do: []
127 - def attachments_from_ids_descs(ids, descs_str) do
128 + def attachments_from_ids_descs(ids, descs_str, user) do
129 {_, descs} = Jason.decode(descs_str)
131 Enum.map(ids, fn media_id ->
132 - with %Object{data: data} <- get_attachment(media_id) do
133 + with %Object{data: data} <- get_attachment(media_id, user) do
134 Map.put(data, "name", descs[media_id])
137 |> Enum.reject(&is_nil/1)
140 - defp get_attachment(media_id) do
141 - Repo.get(Object, media_id)
142 + defp get_attachment(media_id, user) do
143 + with %Object{data: _data} = object <- Repo.get(Object, media_id),
144 + :ok <- Object.authorize_access(object, user) do
151 @spec get_to_and_cc(ActivityDraft.t()) :: {list(String.t()), list(String.t())}
152 diff --git a/mix.exs b/mix.exs
153 index 12f721364dd75744651e5044936d195684d8cf08..e2aac0fc541f2820841a16feff06b058b18ed2ec 100644
156 @@ -4,7 +4,7 @@ defmodule Pleroma.Mixfile do
160 - version: version("2.5.4"),
161 + version: version("2.5.5"),
163 elixirc_paths: elixirc_paths(Mix.env()),
164 compilers: [:phoenix, :gettext] ++ Mix.compilers(),
165 diff --git a/test/pleroma/web/common_api/utils_test.exs b/test/pleroma/web/common_api/utils_test.exs
166 index d309c6deda789fd7818b29e95425b77413b06f7c..c52d3e9c557b6040bb457f40d9ebd02c31975a64 100644
167 --- a/test/pleroma/web/common_api/utils_test.exs
168 +++ b/test/pleroma/web/common_api/utils_test.exs
169 @@ -586,41 +586,56 @@ test "returns recipients when object not found" do
173 - describe "attachments_from_ids_descs/2" do
174 + describe "attachments_from_ids_descs/3" do
175 test "returns [] when attachment ids is empty" do
176 - assert Utils.attachments_from_ids_descs([], "{}") == []
177 + assert Utils.attachments_from_ids_descs([], "{}", nil) == []
180 test "returns list attachments with desc" do
181 - object = insert(:note)
182 + user = insert(:user)
183 + object = insert(:note, %{user: user})
184 desc = Jason.encode!(%{object.id => "test-desc"})
186 - assert Utils.attachments_from_ids_descs(["#{object.id}", "34"], desc) == [
187 + assert Utils.attachments_from_ids_descs(["#{object.id}", "34"], desc, user) == [
188 Map.merge(object.data, %{"name" => "test-desc"})
193 - describe "attachments_from_ids/1" do
194 + describe "attachments_from_ids/2" do
195 test "returns attachments with descs" do
196 - object = insert(:note)
197 + user = insert(:user)
198 + object = insert(:note, %{user: user})
199 desc = Jason.encode!(%{object.id => "test-desc"})
201 - assert Utils.attachments_from_ids(%{
202 - media_ids: ["#{object.id}"],
205 + assert Utils.attachments_from_ids(
207 + media_ids: ["#{object.id}"],
212 Map.merge(object.data, %{"name" => "test-desc"})
216 test "returns attachments without descs" do
217 - object = insert(:note)
218 - assert Utils.attachments_from_ids(%{media_ids: ["#{object.id}"]}) == [object.data]
219 + user = insert(:user)
220 + object = insert(:note, %{user: user})
221 + assert Utils.attachments_from_ids(%{media_ids: ["#{object.id}"]}, user) == [object.data]
224 test "returns [] when not pass media_ids" do
225 - assert Utils.attachments_from_ids(%{}) == []
226 + assert Utils.attachments_from_ids(%{}, nil) == []
229 + test "returns [] when media_ids not belong to current user" do
230 + user = insert(:user)
231 + user2 = insert(:user)
233 + object = insert(:attachment, %{user: user})
235 + assert Utils.attachments_from_ids(%{media_ids: ["#{object.id}"]}, user2) == []
239 diff --git a/test/pleroma/web/common_api_test.exs b/test/pleroma/web/common_api_test.exs
240 index 5c9103e9fc742b8082a432d8ac9ca2ce1929ec32..e60691995c51bdd829f0f67a3abbddc9fe919db9 100644
241 --- a/test/pleroma/web/common_api_test.exs
242 +++ b/test/pleroma/web/common_api_test.exs
243 @@ -279,6 +279,24 @@ test "it reject messages via MRF" do
244 assert {:reject, "[KeywordPolicy] Matches with rejected keyword"} ==
245 CommonAPI.post_chat_message(author, recipient, "GNO/Linux")
248 + test "it reject messages with attachments not belonging to user" do
249 + author = insert(:user)
250 + not_author = insert(:user)
253 + attachment = insert(:attachment, %{user: not_author})
255 + {:error, message} =
256 + CommonAPI.post_chat_message(
260 + media_id: attachment.id
263 + assert message == :forbidden
267 describe "unblocking" do
268 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
269 index e5e510d33b88244b9b088ed93b98bfb2c411dd8b..07a65a3bc1bd09ece6afa2557a719b7550dfae2a 100644
270 --- a/test/pleroma/web/mastodon_api/views/scheduled_activity_view_test.exs
271 +++ b/test/pleroma/web/mastodon_api/views/scheduled_activity_view_test.exs
272 @@ -48,7 +48,7 @@ test "A scheduled activity with a media attachment" do
273 id: to_string(scheduled_activity.id),
275 %{media_ids: [upload.id]}
276 - |> Utils.attachments_from_ids()
277 + |> Utils.attachments_from_ids(user)
278 |> Enum.map(&StatusView.render("attachment.json", %{attachment: &1})),
280 in_reply_to_id: to_string(activity.id),
281 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
282 index 017c9c5c0d2fdf4686d920ea7f05084a6ddf44d7..7ab3f5acdc7971f9ac324db07be30dbff60d680a 100644
283 --- a/test/pleroma/web/pleroma_api/views/chat_message_reference_view_test.exs
284 +++ b/test/pleroma/web/pleroma_api/views/chat_message_reference_view_test.exs
285 @@ -24,7 +24,7 @@ test "it displays a chat message" do
286 filename: "an_image.jpg"
289 - {:ok, upload} = ActivityPub.upload(file, actor: user.ap_id)
290 + {:ok, upload} = ActivityPub.upload(file, actor: recipient.ap_id)
293 CommonAPI.post_chat_message(user, recipient, "kippis :firefox:", idempotency_key: "123")