hj/pleroma
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

fix(fetcher): keep id and author fixed when refetching objects

Browse source 
refetch_object (used for poll updates) accepted whatever the remote
served. A hostile server could swap in another object or move the post
to another author.

The refetch now goes to the stored id without redirects, and the
returned id and actor must equal the stored ones.

Based on Akkoma 9061d148b and fee57eb37.
This commit is contained in:
Lain Soykaf 2026-10-27 21:46:14 +04:00
commit f1337d8159
No known key found for this signature in database
3 changed files with 65 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

12
lib/pleroma/object/fetcher.ex
View file

@ -11,6 +11,7 @@ defmodule Pleroma.Object.Fetcher do
alias Pleroma.Web.ActivityPub.InternalFetchActor
alias Pleroma.Web.ActivityPub.MRF
alias Pleroma.Web.ActivityPub.ObjectValidator
alias Pleroma.Web.ActivityPub.ObjectValidators.CommonFixes
alias Pleroma.Web.ActivityPub.Pipeline
alias Pleroma.Web.ActivityPub.Transmogrifier
alias Pleroma.Web.Federator
@ -46,9 +47,14 @@ defmodule Pleroma.Object.Fetcher do
end
end
def refetch_object(%Object{data: %{"id" => id}} = object) do
# The stored id is canonical, so the refetch must not redirect, and the
# remote must not swap in another object or author.
# Based on Akkoma 9061d148b and fee57eb37.
def refetch_object(%Object{data: %{"id" => id} = data} = object) do
with {:local, false} <- {:local, Object.local?(object)},
{:ok, new_data} <- fetch_and_contain_remote_object_from_id(id),
{:ok, new_data} <- fetch_and_contain(id, true),
{:id, true} <- {:id, new_data["id"] == id},
{:actor, true} <- {:actor, actor_of(new_data) == actor_of(data)},
{:ok, object} <- reinject_object(object, new_data) do
{:ok, object}
else
@ -57,6 +63,8 @@ defmodule Pleroma.Object.Fetcher do
end
end
defp actor_of(data), do: CommonFixes.fix_actor(data)["actor"]
@typep fetcher_errors ::
:error | :reject | :allowed_depth | :fetch | :containment | :transmogrifier