August 1, 2019
Django 1.11.23 fixes security issues in 1.11.22.
django.utils.text.Truncator¶If django.utils.text.Truncator’s chars() and words() methods
were passed the html=True argument, they were extremely slow to evaluate
certain inputs due to a catastrophic backtracking vulnerability in a regular
expression. The chars() and words() methods are used to implement the
truncatechars_html and truncatewords_html template
filters, which were thus vulnerable.
The regular expressions used by Truncator have been simplified in order to
avoid potential backtracking issues. As a consequence, trailing punctuation may
now at times be included in the truncated output.
strip_tags()¶Due to the behavior of the underlying HTMLParser,
django.utils.html.strip_tags() would be extremely slow to evaluate
certain inputs containing large sequences of nested incomplete HTML entities.
The strip_tags() method is used to implement the corresponding
striptags template filter, which was thus also vulnerable.
strip_tags() now avoids recursive calls to HTMLParser when progress
removing tags, but necessarily incomplete HTML entities, stops being made.
Remember that absolutely NO guarantee is provided about the results of
strip_tags() being HTML safe. So NEVER mark safe the result of a
strip_tags() call without escaping it first, for example with
django.utils.html.escape().
JSONField/HStoreField¶Key and index lookups for
JSONField and key lookups for HStoreField
were subject to SQL injection, using a suitably crafted dictionary, with
dictionary expansion, as the **kwargs passed to QuerySet.filter().
django.utils.encoding.uri_to_iri()¶If passed certain inputs, django.utils.encoding.uri_to_iri() could lead
to significant memory usage due to excessive recursion when re-percent-encoding
invalid UTF-8 octet sequences.
uri_to_iri() now avoids recursion when re-percent-encoding invalid UTF-8
octet sequences.
Nov 02, 2020