From d147a8ebbdf28c17cafbbe2884f0bc57e2bf82e2 Mon Sep 17 00:00:00 2001 From: Sarah Boyce <42296566+sarahboyce@users.noreply.github.com> Date: Mon, 12 Aug 2024 15:17:57 +0200 Subject: [4.2.x] Fixed CVE-2024-45230 -- Mitigated potential DoS in urlize and urlizetrunc template filters. Thanks MProgrammer (https://hackerone.com/mprogrammer) for the report. --- django/utils/html.py | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'django/utils/html.py') diff --git a/django/utils/html.py b/django/utils/html.py index 23575d3c11..df38c20519 100644 --- a/django/utils/html.py +++ b/django/utils/html.py @@ -395,14 +395,17 @@ class Urlizer: potential_entity = middle[amp:] escaped = html.unescape(potential_entity) if escaped == potential_entity or escaped.endswith(";"): - 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 + ";" + rstripped = middle.rstrip(self.trailing_punctuation_chars) + trail_start = len(rstripped) + amount_trailing_semicolons = len(middle) - len(middle.rstrip(";")) + if amp > -1 and amount_trailing_semicolons > 1: + # Leave up to most recent semicolon as might be an entity. + recent_semicolon = middle[trail_start:].index(";") + middle_semicolon_index = recent_semicolon + trail_start + 1 + trail = middle[middle_semicolon_index:] + trail + middle = rstripped + middle[trail_start:middle_semicolon_index] else: - trail = middle[len(rstripped) :] + trail + trail = middle[trail_start:] + trail middle = rstripped trimmed_something = True -- cgit v1.3