CVE-2024-4032 (published 2024-06-17T15:15Z)

The “ipaddress” module contained incorrect information about whether certain IPv4 and IPv6 addresses were designated as “globally reachable” or “private”. This affected the is_private and is_global properties of the ipaddress.IPv4Address, ipaddress.IPv4Network, ipaddress.IPv6Address, and ipaddress.IPv6Network classes, where values wouldn’t be returned in accordance with the latest information from the IANA Special-Purpose Address Registries.\n\nCPython 3.12.4 and 3.13.0a6 contain updated information from these registries and thus have the intended behavior.


Weakness information:
cwe_id: NVD-CWE-noinfo
cwe_name: Insufficient Information
description: There is insufficient information about the issue to classify it; details are unkown or unspecified.
extended_description: Insufficient Information

Fix information:
repo_url: https://github.com/python/cpython
commit_details: repo_url: https://github.com/python/cpython
author: Jakub Stasiak
author_date: 2024-03-22 17:49:56+01:00
msg: GH-113171: Fix "private" (non-global) IP address ranges (GH-113179)

* GH-113171: Fix "private" (really non-global) IP address ranges

The _private_networks variables, used by various is_private
implementations, were missing some ranges and at the same time had
overly strict ranges (where there are more specific ranges considered
globally reachable by the IANA registries).

This patch updates the ranges with what was missing or otherwise
incorrect.

I left 100.64.0.0/10 alone, for now, as it's been made special in [1]
and I'm not sure if we want to undo that as I don't quite understand the
motivation behind it.

The _address_exclude_many() call returns 8 networks for IPv4, 121
networks for IPv6.

[1] https://github.com/python/cpython/issues/61602
repository: repo_url: https://github.com/python/cpython
repo_name: python/cpython
description: The Python programming language
repo_language: Python
owner: python
file_changes: filename: ipaddress.rst
change_type: ModificationType.MODIFY
diff: @@ -192,6 +192,18 @@ write code that handles both IP versions correctly.  Address objects are
       ``is_private`` has value opposite to :attr:`is_global`, except for the shared address space
       (``100.64.0.0/10`` range) where they are both ``False``.
 
+      .. versionchanged:: 3.13
+
+         Fixed some false positives and false negatives.
+
+         * ``192.0.0.0/24`` is considered private with the exception of ``192.0.0.9/32`` and
+           ``192.0.0.10/32`` (previously: only the ``192.0.0.0/29`` sub-range was considered private).
+         * ``64:ff9b:1::/48`` is considered private.
+         * ``2002::/16`` is considered private.
+         * There are exceptions within ``2001::/23`` (otherwise considered private): ``2001:1::1/128``,
+           ``2001:1::2/128``, ``2001:3::/32``, ``2001:4:112::/48``, ``2001:20::/28``, ``2001:30::/28``.
+           The exceptions are not considered private.
+
    .. attribute:: is_global
 
       ``True`` if the address is defined as globally reachable by
@@ -209,6 +221,10 @@ write code that handles both IP versions correctly.  Address objects are
 
       .. versionadded:: 3.4
 
+      .. versionchanged:: 3.13
+
+         Fixed some false positives and false negatives, see :attr:`is_private` for details.
+
    .. attribute:: is_unspecified
 
       ``True`` if the address is unspecified.  See :RFC:`5735` (for IPv4)

programming_language: Markdown
filename: 3.13.rst
change_type: ModificationType.MODIFY
diff: @@ -401,6 +401,8 @@ ipaddress
 
 * Add the :attr:`ipaddress.IPv4Address.ipv6_mapped` property, which returns the IPv4-mapped IPv6 address.
   (Contributed by Charles Machalow in :gh:`109466`.)
+* Fix ``is_global`` and ``is_private`` behavior in ``IPv4Address``, ``IPv6Address``, ``IPv4Network``
+  and ``IPv6Network``.
 
 itertools
 ---------

programming_language: Markdown
filename: ipaddress.py
change_type: ModificationType.MODIFY
diff: @@ -1086,7 +1086,11 @@ def is_private(self):
         """
         return any(self.network_address in priv_network and
                    self.broadcast_address in priv_network
-                   for priv_network in self._constants._private_networks)
+                   for priv_network in self._constants._private_networks) and all(
+                    self.network_address not in network and
+                    self.broadcast_address not in network
+                    for network in self._constants._private_networks_exceptions
+                )
 
     @property
     def is_global(self):
@@ -1347,7 +1351,10 @@ def is_private(self):
         ``is_private`` has value opposite to :attr:`is_global`, except for the ``100.64.0.0/10``
         IPv4 range where they are both ``False``.
         """
-        return any(self in net for net in self._constants._private_networks)
+        return (
+            any(self in net for net in self._constants._private_networks)
+            and all(self not in net for net in self._constants._private_networks_exceptions)
+        )
 
     @property
     @functools.lru_cache()
@@ -1578,13 +1585,15 @@ class _IPv4Constants:
 
     _public_network = IPv4Network('100.64.0.0/10')
 
+    # Not globally reachable address blocks listed on
+    # https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
     _private_networks = [
         IPv4Network('0.0.0.0/8'),
         IPv4Network('10.0.0.0/8'),
         IPv4Network('127.0.0.0/8'),
         IPv4Network('169.254.0.0/16'),
         IPv4Network('172.16.0.0/12'),
-        IPv4Network('192.0.0.0/29'),
+        IPv4Network('192.0.0.0/24'),
         IPv4Network('192.0.0.170/31'),
         IPv4Network('192.0.2.0/24'),
         IPv4Network('192.168.0.0/16'),
@@ -1595,6 +1604,11 @@ class _IPv4Constants:
         IPv4Network('255.255.255.255/32'),
         ]
 
+    _private_networks_exceptions = [
+        IPv4Network('192.0.0.9/32'),
+        IPv4Network('192.0.0.10/32'),
+    ]
+
     _reserved_network = IPv4Network('240.0.0.0/4')
 
     _unspecified_address = IPv4Address('0.0.0.0')
@@ -2086,7 +2100,10 @@ def is_private(self):
         ipv4_mapped = self.ipv4_mapped
         if ipv4_mapped is not None:
             return ipv4_mapped.is_private
-        return any(self in net for net in self._constants._private_networks)
+        return (
+            any(self in net for net in self._constants._private_networks)
+            and all(self not in net for net in self._constants._private_networks_exceptions)
+        )
 
     @property
     def is_global(self):
@@ -2342,19 +2359,31 @@ class _IPv6Constants:
 
     _multicast_network = IPv6Network('ff00::/8')
 
+    # Not globally reachable address blocks listed on
+    # https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml
     _private_networks = [
         IPv6Network('::1/128'),
         IPv6Network('::/128'),
         IPv6Network('::ffff:0:0/96'),
+        IPv6Network('64:ff9b:1::/48'),
         IPv6Network('100::/64'),
         IPv6Network('2001::/23'),
-        IPv6Network('2001:2::/48'),
         IPv6Network('2001:db8::/32'),
-        IPv6Network('2001:10::/28'),
+        # IANA says N/A, let's consider it not globally reachable to be safe
+        IPv6Network('2002::/16'),
         IPv6Network('fc00::/7'),
         IPv6Network('fe80::/10'),
         ]
 
+    _private_networks_exceptions = [
+        IPv6Network('2001:1::1/128'),
+        IPv6Network('2001:1::2/128'),
+        IPv6Network('2001:3::/32'),
+        IPv6Network('2001:4:112::/48'),
+        IPv6Network('2001:20::/28'),
+        IPv6Network('2001:30::/28'),
+    ]
+
     _reserved_networks = [
         IPv6Network('::/8'), IPv6Network('100::/8'),
         IPv6Network('200::/7'), IPv6Network('400::/6'),

programming_language: Python
filename: test_ipaddress.py
change_type: ModificationType.MODIFY
diff: @@ -2288,6 +2288,10 @@ def testReservedIpv4(self):
         self.assertEqual(True, ipaddress.ip_address(
                 '172.31.255.255').is_private)
         self.assertEqual(False, ipaddress.ip_address('172.32.0.0').is_private)
+        self.assertFalse(ipaddress.ip_address('192.0.0.0').is_global)
+        self.assertTrue(ipaddress.ip_address('192.0.0.9').is_global)
+        self.assertTrue(ipaddress.ip_address('192.0.0.10').is_global)
+        self.assertFalse(ipaddress.ip_address('192.0.0.255').is_global)
 
         self.assertEqual(True,
                          ipaddress.ip_address('169.254.100.200').is_link_local)
@@ -2313,6 +2317,7 @@ def testPrivateNetworks(self):
         self.assertEqual(True, ipaddress.ip_network("169.254.0.0/16").is_private)
         self.assertEqual(True, ipaddress.ip_network("172.16.0.0/12").is_private)
         self.assertEqual(True, ipaddress.ip_network("192.0.0.0/29").is_private)
+        self.assertEqual(False, ipaddress.ip_network("192.0.0.9/32").is_private)
         self.assertEqual(True, ipaddress.ip_network("192.0.0.170/31").is_private)
         self.assertEqual(True, ipaddress.ip_network("192.0.2.0/24").is_private)
         self.assertEqual(True, ipaddress.ip_network("192.168.0.0/16").is_private)
@@ -2329,8 +2334,8 @@ def testPrivateNetworks(self):
         self.assertEqual(True, ipaddress.ip_network("::/128").is_private)
         self.assertEqual(True, ipaddress.ip_network("::ffff:0:0/96").is_private)
         self.assertEqual(True, ipaddress.ip_network("100::/64").is_private)
-        self.assertEqual(True, ipaddress.ip_network("2001::/23").is_private)
         self.assertEqual(True, ipaddress.ip_network("2001:2::/48").is_private)
+        self.assertEqual(False, ipaddress.ip_network("2001:3::/48").is_private)
         self.assertEqual(True, ipaddress.ip_network("2001:db8::/32").is_private)
         self.assertEqual(True, ipaddress.ip_network("2001:10::/28").is_private)
         self.assertEqual(True, ipaddress.ip_network("fc00::/7").is_private)
@@ -2409,6 +2414,20 @@ def testReservedIpv6(self):
         self.assertEqual(True, ipaddress.ip_address('0::0').is_unspecified)
         self.assertEqual(False, ipaddress.ip_address('::1').is_unspecified)
 
+        self.assertFalse(ipaddress.ip_address('64:ff9b:1::').is_global)
+        self.assertFalse(ipaddress.ip_address('2001::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:1::1').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:1::2').is_global)
+        self.assertFalse(ipaddress.ip_address('2001:2::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:3::').is_global)
+        self.assertFalse(ipaddress.ip_address('2001:4::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:4:112::').is_global)
+        self.assertFalse(ipaddress.ip_address('2001:10::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:20::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:30::').is_global)
+        self.assertFalse(ipaddress.ip_address('2001:40::').is_global)
+        self.assertFalse(ipaddress.ip_address('2002::').is_global)
+
         # some generic IETF reserved addresses
         self.assertEqual(True, ipaddress.ip_address('100::').is_reserved)
         self.assertEqual(True, ipaddress.ip_network('4000::1/128').is_reserved)

programming_language: Python
filename: 2024-03-14-01-38-44.gh-issue-113171.VFnObz.rst
change_type: ModificationType.ADD
diff: @@ -0,0 +1,9 @@
+Fixed various false positives and false negatives in
+
+* :attr:`ipaddress.IPv4Address.is_private` (see these docs for details)
+* :attr:`ipaddress.IPv4Address.is_global`
+* :attr:`ipaddress.IPv6Address.is_private`
+* :attr:`ipaddress.IPv6Address.is_global`
+
+Also in the corresponding :class:`ipaddress.IPv4Network` and :class:`ipaddress.IPv6Network`
+attributes.

programming_language: Markdown