File CVE-2024-38875.patch of Package python-Django

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File CVE-2024-38875.patch of Package python-Django

From 5c13dd367d46ec9efaf70ba15d87c8dfff837aea Mon Sep 17 00:00:00 2001
From: nkrapp <nico.krapp@suse.com>
Date: Fri, 26 Jul 2024 11:19:09 +0200
Subject: [PATCH] [4.2.x] Fixed CVE-2024-38875 -- Mitigated potential
 DoS in urlize and urlizetrunc template filters.

---
 django/utils/html.py           | 73 +++++++++++++++++++++++++++++-----
 tests/utils_tests/test_html.py | 16 +++++++-
 2 files changed, 77 insertions(+), 12 deletions(-)

diff --git a/django/utils/html.py b/django/utils/html.py
index 1ef0b39cdc..517a72372d 100644
--- a/django/utils/html.py
+++ b/django/utils/html.py
@@ -1,5 +1,6 @@
 """HTML utilities suitable for global use."""
 
+import html
 import re
 from urllib.parse import (
     parse_qsl, quote, unquote, urlencode, urlsplit, urlunsplit,
@@ -217,6 +218,16 @@ 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):
     """
@@ -241,6 +252,16 @@ def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False):
             return x
         return '%s...' % x[:max(0, limit - 3)]
 
+    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, trail):
         """
         If input URL is HTML-escaped, unescape it so that it can be safely fed
@@ -264,9 +285,15 @@ 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 trailing punctuation.
@@ -278,15 +305,41 @@ def urlize(text, trim_url_limit=None, nofollow=False, autoescape=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
         return lead, middle, trail
 
diff --git a/tests/utils_tests/test_html.py b/tests/utils_tests/test_html.py
index 077729b069..5f0eefb99e 100644
--- a/tests/utils_tests/test_html.py
+++ b/tests/utils_tests/test_html.py
@@ -219,8 +219,20 @@ 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
+            ("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

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