81 lines
3.1 KiB
Diff
81 lines
3.1 KiB
Diff
|
From 4d8f9e2e4461de92bd1e0c92ed433480d761670f Mon Sep 17 00:00:00 2001
|
||
|
|
From: Ned Deily <nad@python.org>
|
||
|
|
Date: Mon, 19 Oct 2020 22:36:27 -0400
|
||
|
|
Subject: [PATCH] bpo-42051: Reject XML entity declarations in plist files
|
||
|
|
(GH-22760) (GH-22801)
|
||
|
|
|
||
|
|
Co-authored-by: Ronald Oussoren <ronaldoussoren@mac.com>
|
||
|
|
(cherry picked from commit e512bc799e3864fe3b1351757261762d63471efc)
|
||
|
|
|
||
|
|
Co-authored-by: Ned Deily <nad@python.org>
|
||
|
|
---
|
||
|
|
Lib/plistlib.py | 10 +++++
|
||
|
|
Lib/test/test_plistlib.py | 19 ++++++++++
|
||
|
|
Misc/NEWS.d/next/Security/2020-10-19-10-56-27.bpo-42051.EU_B7u.rst | 3 +
|
||
|
|
3 files changed, 32 insertions(+)
|
||
|
|
create mode 100644 Misc/NEWS.d/next/Security/2020-10-19-10-56-27.bpo-42051.EU_B7u.rst
|
||
|
|
|
||
|
|
--- a/Lib/plistlib.py
|
||
|
|
+++ b/Lib/plistlib.py
|
||
|
|
@@ -403,9 +403,19 @@ class PlistParser:
|
||
|
|
parser.StartElementHandler = self.handleBeginElement
|
||
|
|
parser.EndElementHandler = self.handleEndElement
|
||
|
|
parser.CharacterDataHandler = self.handleData
|
||
|
|
+ parser.EntityDeclHandler = self.handle_entity_decl
|
||
|
|
parser.ParseFile(fileobj)
|
||
|
|
return self.root
|
||
|
|
|
||
|
|
+ def handle_entity_decl(self, entity_name, is_parameter_entity, value,
|
||
|
|
+ base, system_id, public_id, notation_name):
|
||
|
|
+ # Reject plist files with entity declarations to avoid XML
|
||
|
|
+ # vulnerabilies in expat. Regular plist files don't contain
|
||
|
|
+ # those declerations, and Apple's plutil tool does not accept
|
||
|
|
+ # them either.
|
||
|
|
+ raise ValueError(
|
||
|
|
+ "XML entity declarations are not supported in plist files")
|
||
|
|
+
|
||
|
|
def handleBeginElement(self, element, attrs):
|
||
|
|
self.data = []
|
||
|
|
handler = getattr(self, "begin_" + element, None)
|
||
|
|
--- a/Lib/test/test_plistlib.py
|
||
|
|
+++ b/Lib/test/test_plistlib.py
|
||
|
|
@@ -86,6 +86,19 @@ TESTDATA = """<?xml version="1.0" encodi
|
||
|
|
</plist>
|
||
|
|
""".replace(" " * 8, "\t") # Apple as well as plistlib.py output hard tabs
|
||
|
|
|
||
|
|
+XML_PLIST_WITH_ENTITY=b'''\
|
||
|
|
+<?xml version="1.0" encoding="UTF-8"?>
|
||
|
|
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd" [
|
||
|
|
+ <!ENTITY entity "replacement text">
|
||
|
|
+ ]>
|
||
|
|
+<plist version="1.0">
|
||
|
|
+ <dict>
|
||
|
|
+ <key>A</key>
|
||
|
|
+ <string>&entity;</string>
|
||
|
|
+ </dict>
|
||
|
|
+</plist>
|
||
|
|
+'''
|
||
|
|
+
|
||
|
|
|
||
|
|
class TestPlistlib(unittest.TestCase):
|
||
|
|
|
||
|
|
@@ -195,6 +208,12 @@ class TestPlistlib(unittest.TestCase):
|
||
|
|
self.assertEqual(test1, result1)
|
||
|
|
self.assertEqual(test2, result2)
|
||
|
|
|
||
|
|
+ def test_xml_plist_with_entity_decl(self):
|
||
|
|
+ with self.assertRaisesRegexp(ValueError,
|
||
|
|
+ "XML entity declarations are not supported"):
|
||
|
|
+ plistlib.readPlistFromString(XML_PLIST_WITH_ENTITY)
|
||
|
|
+
|
||
|
|
+
|
||
|
|
|
||
|
|
def test_main():
|
||
|
|
test_support.run_unittest(TestPlistlib)
|
||
|
|
--- /dev/null
|
||
|
|
+++ b/Misc/NEWS.d/next/Security/2020-10-19-10-56-27.bpo-42051.EU_B7u.rst
|
||
|
|
@@ -0,0 +1,3 @@
|
||
|
|
+The :mod:`plistlib` module no longer accepts entity declarations in XML
|
||
|
|
+plist files to avoid XML vulnerabilities. This should not affect users as
|
||
|
|
+entity declarations are not used in regular plist files.
|