File CVE-2024-56374.patch of Package python-Django.38613
From ad866a1ca3e7d60da888d25d27e46a8adb2ed36e Mon Sep 17 00:00:00 2001
From: Natalia <124304+nessita@users.noreply.github.com>
Date: Mon, 6 Jan 2025 15:51:45 -0300
Subject: [PATCH] [4.2.x] Fixed CVE-2024-56374 -- Mitigated potential DoS in
IPv6 validation.
Thanks Saravana Kumar for the report, and Sarah Boyce and Mariusz
Felisiak for the reviews.
Co-authored-by: Natalia <124304+nessita@users.noreply.github.com>
---
django/db/models/fields/__init__.py | 6 +--
django/forms/fields.py | 7 +++-
django/utils/ipv6.py | 19 +++++++--
docs/ref/forms/fields.txt | 13 +++++-
docs/releases/4.2.18.txt | 12 ++++++
.../field_tests/test_genericipaddressfield.py | 33 ++++++++++++++-
tests/utils_tests/test_ipv6.py | 40 +++++++++++++++++--
7 files changed, 116 insertions(+), 14 deletions(-)
diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index b65948d783ae..0cfba4e0aab6 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -25,7 +25,7 @@
)
from django.utils.duration import duration_microseconds, duration_string
from django.utils.functional import Promise, cached_property
-from django.utils.ipv6 import clean_ipv6_address
+from django.utils.ipv6 import MAX_IPV6_ADDRESS_LENGTH, clean_ipv6_address
from django.utils.itercompat import is_iterable
from django.utils.text import capfirst
from django.utils.translation import gettext_lazy as _
@@ -2160,7 +2160,7 @@ def __init__(
invalid_error_message,
) = validators.ip_address_validators(protocol, unpack_ipv4)
self.default_error_messages["invalid"] = invalid_error_message
- kwargs["max_length"] = 39
+ kwargs["max_length"] = MAX_IPV6_ADDRESS_LENGTH
super().__init__(verbose_name, name, *args, **kwargs)
def check(self, **kwargs):
@@ -2187,7 +2187,7 @@ def deconstruct(self):
kwargs["unpack_ipv4"] = self.unpack_ipv4
if self.protocol != "both":
kwargs["protocol"] = self.protocol
- if kwargs.get("max_length") == 39:
+ if kwargs.get("max_length") == self.max_length:
del kwargs["max_length"]
return name, path, args, kwargs
diff --git a/django/forms/fields.py b/django/forms/fields.py
index 01cd831964ea..e62417f5523b 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -42,7 +42,7 @@
from django.utils import formats
from django.utils.dateparse import parse_datetime, parse_duration
from django.utils.duration import duration_string
-from django.utils.ipv6 import clean_ipv6_address
+from django.utils.ipv6 import MAX_IPV6_ADDRESS_LENGTH, clean_ipv6_address
from django.utils.regex_helper import _lazy_re_compile
from django.utils.translation import gettext_lazy as _
from django.utils.translation import ngettext_lazy
@@ -1284,6 +1284,7 @@ def __init__(self, *, protocol="both", unpack_ipv4=False, **kwargs):
self.default_validators = validators.ip_address_validators(
protocol, unpack_ipv4
)[0]
+ kwargs.setdefault("max_length", MAX_IPV6_ADDRESS_LENGTH)
super().__init__(**kwargs)
def to_python(self, value):
@@ -1291,7 +1292,9 @@ def to_python(self, value):
return ""
value = value.strip()
if value and ":" in value:
- return clean_ipv6_address(value, self.unpack_ipv4)
+ return clean_ipv6_address(
+ value, self.unpack_ipv4, max_length=self.max_length
+ )
return value
diff --git a/django/utils/ipv6.py b/django/utils/ipv6.py
index 88dd6ecb4b84..de41a97f7210 100644
--- a/django/utils/ipv6.py
+++ b/django/utils/ipv6.py
@@ -3,9 +3,22 @@
from django.core.exceptions import ValidationError
from django.utils.translation import gettext_lazy as _
+MAX_IPV6_ADDRESS_LENGTH = 39
+
+
+def _ipv6_address_from_str(ip_str, max_length=MAX_IPV6_ADDRESS_LENGTH):
+ if len(ip_str) > max_length:
+ raise ValueError(
+ f"Unable to convert {ip_str} to an IPv6 address (value too long)."
+ )
+ return ipaddress.IPv6Address(int(ipaddress.IPv6Address(ip_str)))
+
def clean_ipv6_address(
- ip_str, unpack_ipv4=False, error_message=_("This is not a valid IPv6 address.")
+ ip_str,
+ unpack_ipv4=False,
+ error_message=_("This is not a valid IPv6 address."),
+ max_length=MAX_IPV6_ADDRESS_LENGTH,
):
"""
Clean an IPv6 address string.
@@ -24,7 +37,7 @@ def clean_ipv6_address(
Return a compressed IPv6 address or the same value.
"""
try:
- addr = ipaddress.IPv6Address(int(ipaddress.IPv6Address(ip_str)))
+ addr = _ipv6_address_from_str(ip_str, max_length)
except ValueError:
raise ValidationError(error_message, code="invalid")
@@ -41,7 +54,7 @@ def is_valid_ipv6_address(ip_str):
Return whether or not the `ip_str` string is a valid IPv6 address.
"""
try:
- ipaddress.IPv6Address(ip_str)
+ _ipv6_address_from_str(ip_str)
except ValueError:
return False
return True
diff --git a/docs/ref/forms/fields.txt b/docs/ref/forms/fields.txt
index 1a7274e0d1ad..76b4587e21a6 100644
--- a/docs/ref/forms/fields.txt
+++ b/docs/ref/forms/fields.txt
@@ -719,7 +719,7 @@ For each field, we describe the default widget used if you don't specify
* Empty value: ``''`` (an empty string)
* Normalizes to: A string. IPv6 addresses are normalized as described below.
* Validates that the given value is a valid IP address.
- * Error message keys: ``required``, ``invalid``
+ * Error message keys: ``required``, ``invalid``, ``max_length``
The IPv6 address normalization follows :rfc:`4291#section-2.2` section 2.2,
including using the IPv4 format suggested in paragraph 3 of that section, like
@@ -727,7 +727,7 @@ For each field, we describe the default widget used if you don't specify
``2001::1``, and ``::ffff:0a0a:0a0a`` to ``::ffff:10.10.10.10``. All characters
are converted to lowercase.
- Takes two optional arguments:
+ Takes three optional arguments:
.. attribute:: protocol
@@ -742,6 +742,15 @@ For each field, we describe the default widget used if you don't specify
``192.0.2.1``. Default is disabled. Can only be used
when ``protocol`` is set to ``'both'``.
+ .. attribute:: max_length
+
+ Defaults to 39, and behaves the same way as it does for
+ :class:`CharField`.
+
+ .. versionchanged:: 4.2.18
+
+ The default value for ``max_length`` was set to 39 characters.
+
``ImageField``
--------------
diff --git a/tests/forms_tests/field_tests/test_genericipaddressfield.py b/tests/forms_tests/field_tests/test_genericipaddressfield.py
index 80722f5c65c1..ef00a727a468 100644
--- a/tests/forms_tests/field_tests/test_genericipaddressfield.py
+++ b/tests/forms_tests/field_tests/test_genericipaddressfield.py
@@ -1,6 +1,7 @@
from django.core.exceptions import ValidationError
from django.forms import GenericIPAddressField
from django.test import SimpleTestCase
+from django.utils.ipv6 import MAX_IPV6_ADDRESS_LENGTH
class GenericIPAddressFieldTest(SimpleTestCase):
@@ -125,6 +126,35 @@ def test_generic_ipaddress_as_ipv6_only(self):
):
f.clean("1:2")
+ def test_generic_ipaddress_max_length_custom(self):
+ # Valid IPv4-mapped IPv6 address, len 45.
+ addr = "0000:0000:0000:0000:0000:ffff:192.168.100.228"
+ f = GenericIPAddressField(max_length=len(addr))
+ f.clean(addr)
+
+ def test_generic_ipaddress_max_length_validation_error(self):
+ # Valid IPv4-mapped IPv6 address, len 45.
+ addr = "0000:0000:0000:0000:0000:ffff:192.168.100.228"
+
+ cases = [
+ ({}, MAX_IPV6_ADDRESS_LENGTH), # Default value.
+ ({"max_length": len(addr) - 1}, len(addr) - 1),
+ ]
+ for kwargs, max_length in cases:
+ max_length_plus_one = max_length + 1
+ msg = (
+ f"Ensure this value has at most {max_length} characters (it has "
+ f"{max_length_plus_one}).'"
+ )
+ with self.subTest(max_length=max_length):
+ f = GenericIPAddressField(**kwargs)
+ with self.assertRaisesMessage(ValidationError, msg):
+ f.clean("x" * max_length_plus_one)
+ with self.assertRaisesMessage(
+ ValidationError, "This is not a valid IPv6 address."
+ ):
+ f.clean(addr)
+
def test_generic_ipaddress_as_generic_not_required(self):
f = GenericIPAddressField(required=False)
self.assertEqual(f.clean(""), "")
@@ -150,7 +180,8 @@ def test_generic_ipaddress_as_generic_not_required(self):
f.clean(" fe80::223:6cff:fe8a:2e8a "), "fe80::223:6cff:fe8a:2e8a"
)
self.assertEqual(
- f.clean(" 2a02::223:6cff:fe8a:2e8a "), "2a02::223:6cff:fe8a:2e8a"
+ f.clean(" " * MAX_IPV6_ADDRESS_LENGTH + " 2a02::223:6cff:fe8a:2e8a "),
+ "2a02::223:6cff:fe8a:2e8a",
)
with self.assertRaisesMessage(
ValidationError, "'This is not a valid IPv6 address.'"
diff --git a/tests/utils_tests/test_ipv6.py b/tests/utils_tests/test_ipv6.py
index bf78ed91c08f..2d06507fa152 100644
--- a/tests/utils_tests/test_ipv6.py
+++ b/tests/utils_tests/test_ipv6.py
@@ -1,9 +1,17 @@
-import unittest
+import traceback
+from io import StringIO
-from django.utils.ipv6 import clean_ipv6_address, is_valid_ipv6_address
+from django.core.exceptions import ValidationError
+from django.test import SimpleTestCase
+from django.utils.ipv6 import (
+ MAX_IPV6_ADDRESS_LENGTH,
+ clean_ipv6_address,
+ is_valid_ipv6_address,
+)
+from django.utils.version import PY310
-class TestUtilsIPv6(unittest.TestCase):
+class TestUtilsIPv6(SimpleTestCase):
def test_validates_correct_plain_address(self):
self.assertTrue(is_valid_ipv6_address("fe80::223:6cff:fe8a:2e8a"))
self.assertTrue(is_valid_ipv6_address("2a02::223:6cff:fe8a:2e8a"))
@@ -64,3 +72,29 @@ def test_unpacks_ipv4(self):
self.assertEqual(
clean_ipv6_address("::ffff:18.52.18.52", unpack_ipv4=True), "18.52.18.52"
)
+
+ def test_address_too_long(self):
+ addresses = [
+ "0000:0000:0000:0000:0000:ffff:192.168.100.228", # IPv4-mapped IPv6 address
+ "0000:0000:0000:0000:0000:ffff:192.168.100.228%123456", # % scope/zone
+ "fe80::223:6cff:fe8a:2e8a:1234:5678:00000", # MAX_IPV6_ADDRESS_LENGTH + 1
+ ]
+ msg = "This is the error message."
+ value_error_msg = "Unable to convert %s to an IPv6 address (value too long)."
+ for addr in addresses:
+ with self.subTest(addr=addr):
+ self.assertGreater(len(addr), MAX_IPV6_ADDRESS_LENGTH)
+ self.assertEqual(is_valid_ipv6_address(addr), False)
+ with self.assertRaisesMessage(ValidationError, msg) as ctx:
+ clean_ipv6_address(addr, error_message=msg)
+ exception_traceback = StringIO()
+ if PY310:
+ traceback.print_exception(ctx.exception, file=exception_traceback)
+ else:
+ traceback.print_exception(
+ type(ctx.exception),
+ value=ctx.exception,
+ tb=ctx.exception.__traceback__,
+ file=exception_traceback,
+ )
+ self.assertIn(value_error_msg % addr, exception_traceback.getvalue())
