akkoma/lib/mix/tasks/pleroma/security.ex

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# Akkoma: Magically expressive social media
# Copyright © 2024 Akkoma Authors <https://akkoma.dev/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Mix.Tasks.Pleroma.Security do
use Mix.Task
import Ecto.Query
import Mix.Pleroma
alias Pleroma.Config
require Logger
@shortdoc """
Security-related tasks, like e.g. checking for signs past exploits were abused.
"""
# Constants etc
defp local_id_prefix(), do: Pleroma.Web.Endpoint.url() <> "/"
defp local_id_pattern(), do: local_id_prefix() <> "%"
@activity_exts ["activity+json", "activity%2Bjson"]
defp activity_ext_url_patterns() do
for e <- @activity_exts do
for suf <- ["", "?%"] do
# Escape literal % for use in SQL patterns
ee = String.replace(e, "%", "\\%")
"%.#{ee}#{suf}"
end
end
|> List.flatten()
end
# Search for malicious uploads exploiting the lack of Content-Type sanitisation from before 2024-03
def run(["spoof-uploaded"]) do
Logger.put_process_level(self(), :notice)
start_pleroma()
IO.puts("""
+------------------------+
| SPOOF SEARCH UPLOADS |
+------------------------+
Checking if any uploads are using privileged types.
NOTE if attachment deletion is enabled, payloads used
in the past may no longer exist.
""")
do_spoof_uploaded()
end
# Fuzzy search for potentially counterfeit activities in the database resulting from the same exploit
def run(["spoof-inserted"]) do
Logger.put_process_level(self(), :notice)
start_pleroma()
IO.puts("""
+----------------------+
| SPOOF SEARCH NOTES |
+----------------------+
Starting fuzzy search for counterfeit activities.
NOTE this can not guarantee detecting all counterfeits
and may yield a small percentage of false positives.
""")
do_spoof_inserted()
end
# +-----------------------------+
# | S P O O F - U P L O A D E D |
# +-----------------------------+
defp do_spoof_uploaded() do
files =
case Config.get!([Pleroma.Upload, :uploader]) do
Pleroma.Uploaders.Local ->
uploads_search_spoofs_local_dir(Config.get!([Pleroma.Uploaders.Local, :uploads]))
_ ->
IO.puts("""
NOTE:
Not using local uploader; thus not affected by this exploit.
It's impossible to check for files, but in case local uploader was used before
or to check if anyone futilely attempted a spoof, notes will still be scanned.
""")
[]
end
emoji = uploads_search_spoofs_local_dir(Config.get!([:instance, :static_dir]))
post_attachs = uploads_search_spoofs_notes()
not_orphaned_urls =
post_attachs
|> Enum.map(fn {_u, _a, url} -> url end)
|> MapSet.new()
orphaned_attachs = upload_search_orphaned_attachments(not_orphaned_urls)
IO.puts("\nSearch concluded; here are the results:")
pretty_print_list_with_title(emoji, "Emoji")
pretty_print_list_with_title(files, "Uploaded Files")
pretty_print_list_with_title(post_attachs, "(Not Deleted) Post Attachments")
pretty_print_list_with_title(orphaned_attachs, "Orphaned Uploads")
IO.puts("""
In total found
#{length(emoji)} emoji
#{length(files)} uploads
#{length(post_attachs)} not deleted posts
#{length(orphaned_attachs)} orphaned attachments
""")
end
defp uploads_search_spoofs_local_dir(dir) do
local_dir = String.replace_suffix(dir, "/", "")
IO.puts("Searching for suspicious files in #{local_dir}...")
glob_ext = "{" <> Enum.join(@activity_exts, ",") <> "}"
Path.wildcard(local_dir <> "/**/*." <> glob_ext, match_dot: true)
|> Enum.map(fn path ->
String.replace_prefix(path, local_dir <> "/", "")
end)
|> Enum.sort()
end
defp uploads_search_spoofs_notes() do
IO.puts("Now querying DB for posts with spoofing attachments. This might take a while...")
patterns = [local_id_pattern() | activity_ext_url_patterns()]
# if jsonb_array_elemsts in FROM can be used with normal Ecto functions, idk how
"""
SELECT DISTINCT a.data->>'actor', a.id, url->>'href'
FROM public.objects AS o JOIN public.activities AS a
ON o.data->>'id' = a.data->>'object',
jsonb_array_elements(o.data->'attachment') AS attachs,
jsonb_array_elements(attachs->'url') AS url
WHERE o.data->>'type' = 'Note' AND
o.data->>'id' LIKE $1::text AND (
url->>'href' LIKE $2::text OR
url->>'href' LIKE $3::text OR
url->>'href' LIKE $4::text OR
url->>'href' LIKE $5::text
)
ORDER BY a.data->>'actor', a.id, url->>'href';
"""
|> Pleroma.Repo.query!(patterns, timeout: :infinity)
|> map_raw_id_apid_tuple()
end
defp upload_search_orphaned_attachments(not_orphaned_urls) do
IO.puts("""
Now querying DB for orphaned spoofing attachment (i.e. their post was deleted,
but if :cleanup_attachments was not enabled traces remain in the database)
This might take a bit...
""")
patterns = activity_ext_url_patterns()
"""
SELECT DISTINCT attach.id, url->>'href'
FROM public.objects AS attach,
jsonb_array_elements(attach.data->'url') AS url
WHERE (attach.data->>'type' = 'Image' OR
attach.data->>'type' = 'Document')
AND (
url->>'href' LIKE $1::text OR
url->>'href' LIKE $2::text OR
url->>'href' LIKE $3::text OR
url->>'href' LIKE $4::text
)
ORDER BY attach.id, url->>'href';
"""
|> Pleroma.Repo.query!(patterns, timeout: :infinity)
|> then(fn res -> Enum.map(res.rows, fn [id, url] -> {id, url} end) end)
|> Enum.filter(fn {_, url} -> !(url in not_orphaned_urls) end)
end
# +-----------------------------+
# | S P O O F - I N S E R T E D |
# +-----------------------------+
defp do_spoof_inserted() do
IO.puts("""
Searching for local posts whose Create activity has no ActivityPub id...
This is a pretty good indicator, but only for spoofs of local actors
and only if the spoofing happened after around late 2021.
""")
idless_create =
search_local_notes_without_create_id()
|> Enum.sort()
IO.puts("Done.\n")
IO.puts("""
Now trying to weed out other poorly hidden spoofs.
This can't detect all and may have some false positives.
""")
likely_spoofed_posts_set = MapSet.new(idless_create)
sus_pattern_posts =
search_sus_notes_by_id_patterns()
|> Enum.filter(fn r -> !(r in likely_spoofed_posts_set) end)
IO.puts("Done.\n")
IO.puts("""
Finally, searching for spoofed, local user accounts.
(It's impossible to detect spoofed remote users)
""")
spoofed_users = search_bogus_local_users()
pretty_print_list_with_title(sus_pattern_posts, "Maybe Spoofed Posts")
pretty_print_list_with_title(idless_create, "Likely Spoofed Posts")
pretty_print_list_with_title(spoofed_users, "Spoofed local user accounts")
IO.puts("""
In total found:
#{length(spoofed_users)} bogus users
#{length(idless_create)} likely spoofed posts
#{length(sus_pattern_posts)} maybe spoofed posts
""")
end
defp search_local_notes_without_create_id() do
Pleroma.Object
|> where([o], fragment("?->>'id' LIKE ?", o.data, ^local_id_pattern()))
|> join(:inner, [o], a in Pleroma.Activity,
on: fragment("?->>'object' = ?->>'id'", a.data, o.data)
)
|> where([o, a], fragment("NOT (? \\? 'id') OR ?->>'id' IS NULL", a.data, a.data))
|> select([o, a], {a.id, fragment("?->>'id'", o.data)})
|> order_by([o, a], a.id)
|> Pleroma.Repo.all(timeout: :infinity)
end
defp search_sus_notes_by_id_patterns() do
[ep1, ep2, ep3, ep4] = activity_ext_url_patterns()
Pleroma.Object
|> where(
[o],
# for local objects we know exactly how a genuine id looks like
# (though a thorough attacker can emulate this)
# for remote posts, use some best-effort patterns
fragment(
"""
(?->>'id' LIKE ? AND ?->>'id' NOT SIMILAR TO
? || 'objects/[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}')
""",
o.data,
^local_id_pattern(),
o.data,
^local_id_prefix()
) or
fragment("?->>'id' LIKE ?", o.data, "%/emoji/%") or
fragment("?->>'id' LIKE ?", o.data, "%/media/%") or
fragment("?->>'id' LIKE ?", o.data, "%/proxy/%") or
fragment("?->>'id' LIKE ?", o.data, ^ep1) or
fragment("?->>'id' LIKE ?", o.data, ^ep2) or
fragment("?->>'id' LIKE ?", o.data, ^ep3) or
fragment("?->>'id' LIKE ?", o.data, ^ep4)
)
|> join(:inner, [o], a in Pleroma.Activity,
on: fragment("?->>'object' = ?->>'id'", a.data, o.data)
)
|> select([o, a], {a.id, fragment("?->>'id'", o.data)})
|> order_by([o, a], a.id)
|> Pleroma.Repo.all(timeout: :infinity)
end
defp search_bogus_local_users() do
Pleroma.User.Query.build(%{})
|> where([u], u.local == false and like(u.ap_id, ^local_id_pattern()))
|> order_by([u], u.ap_id)
|> select([u], u.ap_id)
|> Pleroma.Repo.all(timeout: :infinity)
end
# +-----------------------------------+
# | module-specific utility functions |
# +-----------------------------------+
defp pretty_print_list_with_title(list, title) do
title_len = String.length(title)
title_underline = String.duplicate("=", title_len)
IO.puts(title)
IO.puts(title_underline)
pretty_print_list(list)
end
defp pretty_print_list([]), do: IO.puts("")
defp pretty_print_list([{a, o} | rest])
when (is_binary(a) or is_number(a)) and is_binary(o) do
IO.puts(" {#{a}, #{o}}")
pretty_print_list(rest)
end
defp pretty_print_list([{u, a, o} | rest])
when is_binary(a) and is_binary(u) and is_binary(o) do
IO.puts(" {#{u}, #{a}, #{o}}")
pretty_print_list(rest)
end
defp pretty_print_list([e | rest]) when is_binary(e) do
IO.puts(" #{e}")
pretty_print_list(rest)
end
defp pretty_print_list([e | rest]), do: pretty_print_list([inspect(e) | rest])
defp map_raw_id_apid_tuple(res) do
user_prefix = local_id_prefix() <> "users/"
Enum.map(res.rows, fn
[uid, aid, oid] ->
{
String.replace_prefix(uid, user_prefix, ""),
FlakeId.to_string(aid),
oid
}
end)
end
end