Merge remote-tracking branch 'upstream/develop' into patch420

CHANGELOG.md

@@ -18,6 +18,17 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Removed
 - BREAKING: Support for passwords generated with `crypt(3)` (Gnu Social migration artifact)
 
+## 2.5.4
+
+## Security
+- Fix XML External Entity (XXE) loading vulnerability allowing to fetch arbitary files from the server's filesystem
+
+## 2.5.3
+
+### Security
+- Emoji pack loader sanitizes pack names
+- Reduced permissions of config files and directories, distros requiring greater permissions like group-read need to pre-create the directories
+
 ## 2.5.2
 
 ### Security

changelog.d/akkoma-xml-remote-entities.security

@@ -0,0 +1 @@
+Fix XML External Entity (XXE) loading vulnerability allowing to fetch arbitary files from the server's filesystem

changelog.d/emoji-pack-sanitization.security

@@ -0,0 +1 @@
+Emoji pack loader sanitizes pack names

changelog.d/otp_perms.security

@@ -0,0 +1 @@
+- Reduced permissions of config files and directories, distros requiring greater permissions like group-read need to pre-create the directories

docs/installation/gentoo_otp_en.md

@@ -2,7 +2,7 @@
 
 {! backend/installation/otp_vs_from_source.include !}
 
-A [manual installation guide for gentoo](./gentoo_en.md) is also available.
+This guide covers installation via Gentoo provided packaging. A [manual installation guide for gentoo](./gentoo_en.md) is also available.
 
 ## Installation
 

lib/mix/tasks/pleroma/instance.ex

@@ -266,12 +266,20 @@ defmodule Mix.Tasks.Pleroma.Instance do
       config_dir = Path.dirname(config_path)
       psql_dir = Path.dirname(psql_path)
 
+      # Note: Distros requiring group read (0o750) on those directories should
+      # pre-create the directories.
       [config_dir, psql_dir, static_dir, uploads_dir]
       |> Enum.reject(&File.exists?/1)
-      |> Enum.map(&File.mkdir_p!/1)
+      |> Enum.each(fn dir ->
+        File.mkdir_p!(dir)
+        File.chmod!(dir, 0o700)
+      end)
 
       shell_info("Writing config to #{config_path}.")
 
+      # Sadly no fchmod(2) equivalent in Elixir…
+      File.touch!(config_path)
+      File.chmod!(config_path, 0o640)
       File.write(config_path, result_config)
       shell_info("Writing the postgres script to #{psql_path}.")
       File.write(psql_path, result_psql)
@@ -290,8 +298,7 @@ defmodule Mix.Tasks.Pleroma.Instance do
     else
       shell_error(
         "The task would have overwritten the following files:\n" <>
-          (Enum.map(will_overwrite, &"- #{&1}\n") |> Enum.join("")) <>
+          Enum.map_join(will_overwrite, &"- #{&1}\n") <> "Rerun with `--force` to overwrite them."
-          "Rerun with `--force` to overwrite them."
       )
     end
   end

lib/pleroma/config/release_runtime_provider.ex

@@ -20,6 +20,20 @@ defmodule Pleroma.Config.ReleaseRuntimeProvider do
 
     with_runtime_config =
       if File.exists?(config_path) do
+        # <https://git.pleroma.social/pleroma/pleroma/-/issues/3135>
+        %File.Stat{mode: mode} = File.lstat!(config_path)
+
+        if Bitwise.band(mode, 0o007) > 0 do
+          raise "Configuration at #{config_path} has world-permissions, execute the following: chmod o= #{config_path}"
+        end
+
+        if Bitwise.band(mode, 0o020) > 0 do
+          raise "Configuration at #{config_path} has group-wise write permissions, execute the following: chmod g-w #{config_path}"
+        end
+
+        # Note: Elixir doesn't provides a getuid(2)
+        # so cannot forbid group-read only when config is owned by us
+
         runtime_config = Config.Reader.read!(config_path)
 
         with_defaults

lib/pleroma/emoji/pack.ex

@@ -285,6 +285,7 @@ defmodule Pleroma.Emoji.Pack do
 
   @spec load_pack(String.t()) :: {:ok, t()} | {:error, :file.posix()}
   def load_pack(name) do
+    name = Path.basename(name)
     pack_file = Path.join([emoji_path(), name, "pack.json"])
 
     with {:ok, _} <- File.stat(pack_file),

lib/pleroma/web/xml.ex

@@ -29,7 +29,10 @@ defmodule Pleroma.Web.XML do
       {doc, _rest} =
         text
         |> :binary.bin_to_list()
-        |> :xmerl_scan.string(quiet: true)
+        |> :xmerl_scan.string(
+          quiet: true,
+          fetch_fun: fn _, _ -> raise "Resolving external entities not supported" end
+        )
 
       {:ok, doc}
     rescue

mix.exs

@@ -4,7 +4,7 @@ defmodule Pleroma.Mixfile do
   def project do
     [
       app: :pleroma,
-      version: version("2.5.52"),
+      version: version("2.5.54"),
       elixir: "~> 1.11",
       elixirc_paths: elixirc_paths(Mix.env()),
       compilers: [:phoenix] ++ Mix.compilers(),

test/fixtures/xml_external_entities.xml

@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE foo [ <!ENTITY xxe SYSTEM "file:///etc/passwd"> ]>
+<stockCheck><productId>&xxe;</productId></stockCheck>

test/pleroma/config/release_runtime_provider_test.exs

@@ -17,6 +17,8 @@ defmodule Pleroma.Config.ReleaseRuntimeProviderTest do
     end
 
     test "merged runtime config" do
+      assert :ok == File.chmod!("test/fixtures/config/temp.secret.exs", 0o640)
+
       merged =
         ReleaseRuntimeProvider.load([], config_path: "test/fixtures/config/temp.secret.exs")
 
@@ -25,6 +27,8 @@ defmodule Pleroma.Config.ReleaseRuntimeProviderTest do
     end
 
     test "merged exported config" do
+      assert :ok == File.chmod!("test/fixtures/config/temp.exported_from_db.secret.exs", 0o640)
+
       ExUnit.CaptureIO.capture_io(fn ->
         merged =
           ReleaseRuntimeProvider.load([],
@@ -37,6 +41,9 @@ defmodule Pleroma.Config.ReleaseRuntimeProviderTest do
     end
 
     test "runtime config is merged with exported config" do
+      assert :ok == File.chmod!("test/fixtures/config/temp.secret.exs", 0o640)
+      assert :ok == File.chmod!("test/fixtures/config/temp.exported_from_db.secret.exs", 0o640)
+
       merged =
         ReleaseRuntimeProvider.load([],
           config_path: "test/fixtures/config/temp.secret.exs",

test/pleroma/emoji/pack_test.exs

@@ -90,4 +90,8 @@ defmodule Pleroma.Emoji.PackTest do
 
     assert updated_pack.files_count == 1
   end
+
+  test "load_pack/1 ignores path traversal in a forged pack name", %{pack: pack} do
+    assert {:ok, ^pack} = Pack.load_pack("../../../../../dump_pack")
+  end
 end

test/pleroma/web/web_finger_test.exs

@@ -180,5 +180,28 @@ defmodule Pleroma.Web.WebFingerTest do
 
       {:ok, _data} = WebFinger.finger("pekorino@pawoo.net")
     end
+
+    test "refuses to process XML remote entities" do
+      Tesla.Mock.mock(fn
+        %{
+          url: "https://pawoo.net/.well-known/webfinger?resource=acct:pekorino@pawoo.net"
+        } ->
+          {:ok,
+           %Tesla.Env{
+             status: 200,
+             body: File.read!("test/fixtures/xml_external_entities.xml"),
+             headers: [{"content-type", "application/xrd+xml"}]
+           }}
+
+        %{url: "https://pawoo.net/.well-known/host-meta"} ->
+          {:ok,
+           %Tesla.Env{
+             status: 200,
+             body: File.read!("test/fixtures/tesla_mock/pawoo.net_host_meta")
+           }}
+      end)
+
+      assert :error = WebFinger.finger("pekorino@pawoo.net")
+    end
   end
 end

test/pleroma/web/xml_test.exs

@@ -0,0 +1,10 @@
+defmodule Pleroma.Web.XMLTest do
+  use Pleroma.DataCase, async: true
+
+  alias Pleroma.Web.XML
+
+  test "refuses to load external entities from XML" do
+    data = File.read!("test/fixtures/xml_external_entities.xml")
+    assert(:error == XML.parse_document(data))
+  end
+end