From efea1ef7e2190e3f77ca0651b5458297bc0f6a9f Mon Sep 17 00:00:00 2001 From: Mariusz Felisiak Date: Wed, 10 Jul 2024 20:30:12 +0200 Subject: [PATCH] [4.2.x] Fixed CVE-2024-41991 -- Prevented potential ReDoS in django.utils.html.urlize() and AdminURLFieldWidget. Thanks Seokchan Yoon for the report. Co-authored-by: Sarah Boyce <42296566+sarahboyce@users.noreply.github.com> CVE: CVE-2024-41991 Upstream-Status: Backport [https://github.com/django/django/commit/efea1ef7e2190e3f77ca0651b5458297bc0f6a9f] Signed-off-by: Soumya Sambu --- django/contrib/admin/widgets.py | 2 +- django/utils/html.py | 10 ++++++++-- tests/admin_widgets/tests.py | 7 ++++++- tests/utils_tests/test_html.py | 13 +++++++++++++ 4 files changed, 28 insertions(+), 4 deletions(-) diff --git a/django/contrib/admin/widgets.py b/django/contrib/admin/widgets.py index a56baee..47647e8 100644 --- a/django/contrib/admin/widgets.py +++ b/django/contrib/admin/widgets.py @@ -344,7 +344,7 @@ class AdminURLFieldWidget(forms.URLInput): context = super().get_context(name, value, attrs) context['current_label'] = _('Currently:') context['change_label'] = _('Change:') - context['widget']['href'] = smart_urlquote(context['widget']['value']) if value else '' + context['widget']['href'] = smart_urlquote(context['widget']['value']) if url_valid else '' context['url_valid'] = url_valid return context diff --git a/django/utils/html.py b/django/utils/html.py index 84e157d..52a3389 100644 --- a/django/utils/html.py +++ b/django/utils/html.py @@ -12,6 +12,8 @@ from django.utils.http import RFC3986_GENDELIMS, RFC3986_SUBDELIMS from django.utils.safestring import SafeData, SafeText, mark_safe from django.utils.text import normalize_newlines +MAX_URL_LENGTH = 2048 + # Configuration for urlize() function. TRAILING_PUNCTUATION_CHARS = '.,:;!' WRAPPING_PUNCTUATION = [('(', ')'), ('[', ']')] @@ -353,6 +355,10 @@ def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False): except ValueError: # value contains more than one @. return False + # Max length for domain name labels is 63 characters per RFC 1034. + # Helps to avoid ReDoS vectors in the domain part. + if len(p2) > 63: + return False # Dot must be in p2 (e.g. example.com) if '.' not in p2 or p2.startswith('.'): return False @@ -371,9 +377,9 @@ def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False): # Make URL we want to point to. url = None nofollow_attr = ' rel="nofollow"' if nofollow else '' - if simple_url_re.match(middle): + if len(middle) <= MAX_URL_LENGTH and simple_url_re.match(middle): url = smart_urlquote(unescape(middle)) - elif simple_url_2_re.match(middle): + elif len(middle) <= MAX_URL_LENGTH and simple_url_2_re.match(middle): url = smart_urlquote('http://%s' % unescape(middle)) elif ':' not in middle and is_email_simple(middle): local, domain = middle.rsplit('@', 1) diff --git a/tests/admin_widgets/tests.py b/tests/admin_widgets/tests.py index 4c14a47..e373f1a 100644 --- a/tests/admin_widgets/tests.py +++ b/tests/admin_widgets/tests.py @@ -336,7 +336,12 @@ class AdminSplitDateTimeWidgetTest(SimpleTestCase): class AdminURLWidgetTest(SimpleTestCase): def test_get_context_validates_url(self): w = widgets.AdminURLFieldWidget() - for invalid in ['', '/not/a/full/url/', 'javascript:alert("Danger XSS!")']: + for invalid in [ + "", + "/not/a/full/url/", + 'javascript:alert("Danger XSS!")', + "http://" + "한.글." * 1_000_000 + "com", + ]: with self.subTest(url=invalid): self.assertFalse(w.get_context('name', invalid, {})['url_valid']) self.assertTrue(w.get_context('name', 'http://example.com', {})['url_valid']) diff --git a/tests/utils_tests/test_html.py b/tests/utils_tests/test_html.py index 5abab8d..1956655 100644 --- a/tests/utils_tests/test_html.py +++ b/tests/utils_tests/test_html.py @@ -254,6 +254,15 @@ class TestUtilsHtml(SimpleTestCase): ), ('foo@example.com', 'foo@example.com'), ) + ( + "test@" + "한.글." * 15 + "aaa", + '' + + "test@" + + "한.글." * 15 + + "aaa", + ), for value, output in tests: with self.subTest(value=value): self.assertEqual(urlize(value), output) @@ -261,6 +270,10 @@ class TestUtilsHtml(SimpleTestCase): def test_urlize_unchanged_inputs(self): tests = ( ('a' + '@a' * 50000) + 'a', # simple_email_re catastrophic test + # Unicode domain catastrophic tests. + "a@" + "한.글." * 1_000_000 + "a", + "http://" + "한.글." * 1_000_000 + "com", + "www." + "한.글." * 1_000_000 + "com", ('a' + '.' * 1000000) + 'a', # trailing_punctuation catastrophic test 'foo@', '@foo.com', -- 2.40.0