October 4, 2023
Django 4.1.12 fixes a security issue with severity “moderate” in 4.1.11.
django.utils.text.Truncator¶Following the fix for CVE-2019-14232, the regular expressions used in the
implementation of django.utils.text.Truncator’s chars() and words()
methods (with html=True) were revised and improved. However, these regular
expressions still exhibited linear backtracking complexity, so when given a
very long, potentially malformed HTML input, the evaluation would still be
slow, leading to a potential denial of service vulnerability.
The chars() and words() methods are used to implement the
truncatechars_html and truncatewords_html template
filters, which were thus also vulnerable.
The input processed by Truncator, when operating in HTML mode, has been
limited to the first five million characters in order to avoid potential
performance and memory issues.
May 02, 2024