CVE-2019-14232: Denial-of-service possibility in
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.
CVE-2019-14233: Denial-of-service possibility in 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().
CVE-2019-14234: SQL injection possibility in key and index lookups for
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().
CVE-2019-14235: Potential memory exhaustion in
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.