86 lines
3.3 KiB
Diff
86 lines
3.3 KiB
Diff
From 9cd8028f3e38dca8e51c1388f474eecbe7d6ca3c Mon Sep 17 00:00:00 2001
|
|
From: Sarah Boyce <42296566+sarahboyce@users.noreply.github.com>
|
|
Date: Tue, 8 Apr 2025 16:30:17 +0200
|
|
Subject: [PATCH] [4.2.x] Fixed CVE-2025-32873 -- Mitigated potential DoS in
|
|
strip_tags().
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
Thanks to Elias Myllymäki for the report, and Shai Berger and Jake
|
|
Howard for the reviews.
|
|
|
|
Co-authored-by: Natalia <124304+nessita@users.noreply.github.com>
|
|
|
|
Backport of 9f3419b519799d69f2aba70b9d25abe2e70d03e0 from main.
|
|
|
|
Origin: https://github.com/django/django/commit/9cd8028f3e38dca8e51c1388f474eecbe7d6ca3c
|
|
---
|
|
django/utils/html.py | 6 ++++++
|
|
tests/utils_tests/test_html.py | 15 ++++++++++++++-
|
|
2 files changed, 20 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/django/utils/html.py b/django/utils/html.py
|
|
index a3a7238..84c37d1 100644
|
|
--- a/django/utils/html.py
|
|
+++ b/django/utils/html.py
|
|
@@ -17,6 +17,9 @@ from django.utils.text import normalize_newlines
|
|
MAX_URL_LENGTH = 2048
|
|
MAX_STRIP_TAGS_DEPTH = 50
|
|
|
|
+# HTML tag that opens but has no closing ">" after 1k+ chars.
|
|
+long_open_tag_without_closing_re = _lazy_re_compile(r"<[a-zA-Z][^>]{1000,}")
|
|
+
|
|
|
|
@keep_lazy(SafeString)
|
|
def escape(text):
|
|
@@ -175,6 +178,9 @@ def _strip_once(value):
|
|
def strip_tags(value):
|
|
"""Return the given HTML with all tags stripped."""
|
|
value = str(value)
|
|
+ for long_open_tag in long_open_tag_without_closing_re.finditer(value):
|
|
+ if long_open_tag.group().count("<") >= MAX_STRIP_TAGS_DEPTH:
|
|
+ raise SuspiciousOperation
|
|
# Note: in typical case this loop executes _strip_once twice (the second
|
|
# execution does not remove any more tags).
|
|
strip_tags_depth = 0
|
|
diff --git a/tests/utils_tests/test_html.py b/tests/utils_tests/test_html.py
|
|
index 579bb2a..25168e2 100644
|
|
--- a/tests/utils_tests/test_html.py
|
|
+++ b/tests/utils_tests/test_html.py
|
|
@@ -115,17 +115,30 @@ class TestUtilsHtml(SimpleTestCase):
|
|
("><!" + ("&" * 16000) + "D", "><!" + ("&" * 16000) + "D"),
|
|
("X<<<<br>br>br>br>X", "XX"),
|
|
("<" * 50 + "a>" * 50, ""),
|
|
+ (">" + "<a" * 500 + "a", ">" + "<a" * 500 + "a"),
|
|
+ ("<a" * 49 + "a" * 951, "<a" * 49 + "a" * 951),
|
|
+ ("<" + "a" * 1_002, "<" + "a" * 1_002),
|
|
)
|
|
for value, output in items:
|
|
with self.subTest(value=value, output=output):
|
|
self.check_output(strip_tags, value, output)
|
|
self.check_output(strip_tags, lazystr(value), output)
|
|
|
|
- def test_strip_tags_suspicious_operation(self):
|
|
+ def test_strip_tags_suspicious_operation_max_depth(self):
|
|
value = "<" * 51 + "a>" * 51, "<a>"
|
|
with self.assertRaises(SuspiciousOperation):
|
|
strip_tags(value)
|
|
|
|
+ def test_strip_tags_suspicious_operation_large_open_tags(self):
|
|
+ items = [
|
|
+ ">" + "<a" * 501,
|
|
+ "<a" * 50 + "a" * 950,
|
|
+ ]
|
|
+ for value in items:
|
|
+ with self.subTest(value=value):
|
|
+ with self.assertRaises(SuspiciousOperation):
|
|
+ strip_tags(value)
|
|
+
|
|
def test_strip_tags_files(self):
|
|
# Test with more lengthy content (also catching performance regressions)
|
|
for filename in ("strip_tags1.html", "strip_tags2.txt"):
|
|
--
|
|
2.49.0
|
|
|