File CVE-2024-38875.patch of Package python-Django.18539
From 8623260fb0949d368376a128bee2189ec0a67ae5 Mon Sep 17 00:00:00 2001
From: nkrapp <nico.krapp@suse.com>
Date: Mon, 22 Jul 2024 09:43:08 +0200
Subject: [PATCH] [PATCH] [4.2.x] Fixed CVE-2024-38875 -- Mitigated potential
DoS in urlize and urlizetrunc template filters.
---
django/utils/html.py | 72 +++++++++++++++++++++++++++++-----
tests/utils_tests/test_html.py | 21 ++++++----
2 files changed, 75 insertions(+), 17 deletions(-)
diff --git a/django/utils/html.py b/django/utils/html.py
index 7a33d5f68d..1dbe39ccd1 100644
--- a/django/utils/html.py
+++ b/django/utils/html.py
@@ -1,5 +1,6 @@
"""HTML utilities suitable for global use."""
+import html
import json
import re
from html.parser import HTMLParser
@@ -235,6 +235,16 @@ def smart_urlquote(url):
return urlunsplit((scheme, netloc, path, query, fragment))
+class CountsDict(dict):
+ def __init__(self, *args, word, **kwargs):
+ super().__init__(*args, *kwargs)
+ self.word = word
+
+ def __missing__(self, key):
+ self[key] = self.word.count(key)
+ return self[key]
+
+
@keep_lazy_text
def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False):
"""
@@ -259,6 +269,15 @@ def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False):
return x
return '%s…' % x[:max(0, limit - 1)]
+ def wrapping_punctuation_openings():
+ return "".join(dict(WRAPPING_PUNCTUATION).keys())
+
+ def trailing_punctuation_chars_no_semicolon():
+ return TRAILING_PUNCTUATION_CHARS.replace(";", "")
+
+ def trailing_punctuation_chars_has_semicolon():
+ return ";" in TRAILING_PUNCTUATION_CHARS
+
def unescape(text):
"""
If input URL is HTML-escaped, unescape it so that it can be safely fed
@@ -273,21 +292,53 @@ def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False):
Trim trailing and wrapping punctuation from `middle`. Return the items
of the new state.
"""
+ # Strip all opening wrapping punctuation.
+ middle = word.lstrip(wrapping_punctuation_openings())
+ lead = word[: len(word) - len(middle)]
+ trail = ""
+
# Continue trimming until middle remains unchanged.
trimmed_something = True
- while trimmed_something:
+ counts = CountsDict(word=middle)
+ while trimmed_something and middle:
trimmed_something = False
# Trim wrapping punctuation.
for opening, closing in WRAPPING_PUNCTUATION:
- if middle.startswith(opening):
- middle = middle[len(opening):]
- lead += opening
- trimmed_something = True
- # Keep parentheses at the end only if they're balanced.
- if (middle.endswith(closing) and
- middle.count(closing) == middle.count(opening) + 1):
- middle = middle[:-len(closing)]
- trail = closing + trail
+ if counts[opening] < counts[closing]:
+ rstripped = middle.rstrip(closing)
+ if rstripped != middle:
+ strip = counts[closing] - counts[opening]
+ trail = middle[-strip:]
+ middle = middle[:-strip]
+ trimmed_something = True
+ counts[closing] -= strip
+
+ rstripped = middle.rstrip(trailing_punctuation_chars_no_semicolon())
+ if rstripped != middle:
+ trail = middle[len(rstripped) :] + trail
+ middle = rstripped
+ trimmed_something = True
+
+ if trailing_punctuation_chars_has_semicolon() and middle.endswith(";"):
+ # Only strip if not part of an HTML entity.
+ amp = middle.rfind("&")
+ if amp == -1:
+ can_strip = True
+ else:
+ potential_entity = middle[amp:]
+ escaped = html.unescape(potential_entity)
+ can_strip = (escaped == potential_entity) or escaped.endswith(";")
+
+ if can_strip:
+ rstripped = middle.rstrip(";")
+ amount_stripped = len(middle) - len(rstripped)
+ if amp > -1 and amount_stripped > 1:
+ # Leave a trailing semicolon as might be an entity.
+ trail = middle[len(rstripped) + 1 :] + trail
+ middle = rstripped + ";"
+ else:
+ trail = middle[len(rstripped) :] + trail
+ middle = rstripped
trimmed_something = True
# Trim trailing punctuation (after trimming wrapping punctuation,
# as encoded entities contain ';'). Unescape entites to avoid
diff --git a/tests/utils_tests/test_html.py b/tests/utils_tests/test_html.py
index 5cc2d9b95d..dc89009b63 100644
--- a/tests/utils_tests/test_html.py
+++ b/tests/utils_tests/test_html.py
@@ -260,13 +260,20 @@ class TestUtilsHtml(SimpleTestCase):
def test_urlize_unchanged_inputs(self):
tests = (
- ('a' + '@a' * 50000) + 'a', # simple_email_re catastrophic test
- ('a' + '.' * 1000000) + 'a', # trailing_punctuation catastrophic test
- 'foo@',
- '@foo.com',
- 'foo@.example.com',
- 'foo@localhost',
- 'foo@localhost.',
+ ("a" + "@a" * 50000) + "a", # simple_email_re catastrophic test
+ ("a" + "." * 1000000) + "a", # trailing_punctuation catastrophic test
+ "foo@",
+ "@foo.com",
+ "foo@.example.com",
+ "foo@localhost",
+ "foo@localhost.",
+ # trim_punctuation catastrophic tests
+ "(" * 100_000 + ":" + ")" * 100_000,
+ "(" * 100_000 + "&:" + ")" * 100_000,
+ "([" * 100_000 + ":" + "])" * 100_000,
+ "[(" * 100_000 + ":" + ")]" * 100_000,
+ "([[" * 100_000 + ":" + "]])" * 100_000,
+ "&:" + ";" * 100_000,
)
for value in tests:
with self.subTest(value=value):
--
2.45.2
