Fixes the following security issues:
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 django.contrib.postgres.fields.JSONField and key
lookups for django.contrib.postgres.fields.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.
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
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