In Mozilla Bleach before 3.12, a mutation XSS in bleach.clean when RCDATA and either svg or math tags are whitelisted and the keyword argument strip=False.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - In Mozilla Bleach before 3.12, a mutation XSS in bleach.clean when RCDATA and either svg or math tags are     whitelisted and the keyword argument strip=False. (CVE-2020-6816)

Note that Nessus relies on the presence of the package as reported by the vendor.

This update for python-bleach fixes the following issues :

  - CVE-2021-23980: Fixed mutation XSS on bleach.clean with     specific combinations of allowed tags (boo#1184547)

Update to 3.1.5 :

  - replace missing ``setuptools`` dependency with     ``packaging``. Thank you Benjamin Peterson.

Update to 3.1.4 (boo#1168280, CVE-2020-6817) :

  - ``bleach.clean`` behavior parsing style attributes could     result in a regular expression denial of service     (ReDoS). Calls to ``bleach.clean`` with an allowed tag     with an allowed ``style`` attribute were vulnerable to     ReDoS. For example, ``bleach.clean(..., attributes=('a':
    ['style']))``.

  - Style attributes with dashes, or single or double quoted     values are cleaned instead of passed through.

update to 3.1.3 (boo#1167379, CVE-2020-6816) :

  - Add relative link to code of conduct. (#442)

  - Drop deprecated 'setup.py test' support. (#507)

  - Fix typo: curren -> current in tests/test_clean.py     (#504)

  - Test on PyPy 7

  - Drop test support for end of life Python 3.4

  - ``bleach.clean`` behavior parsing embedded MathML and     SVG content with RCDATA tags did not match browser     behavior and could result in a mutation XSS. Calls to     ``bleach.clean`` with ``strip=False`` and ``math`` or     ``svg`` tags and one or more of the RCDATA tags     ``script``, ``noscript``, ``style``, ``noframes``,     ``iframe``, ``noembed``, or ``xmp`` in the allowed tags     whitelist were vulnerable to a mutation XSS.

It was reported that python-bleach, a whitelist-based HTML-sanitizing library, is prone to a mutation XSS vulnerability in bleach.clean when strip=False and 'math' or 'svg' tags and one or more of the RCDATA tags were whitelisted.

ID	Name	Product	Family	Severity
250497	Linux Distros Unpatched Vulnerability : CVE-2020-6816	Nessus	Misc.	medium
148606	openSUSE Security Update : python-bleach (openSUSE-2021-552)	Nessus	SuSE Local Security Checks	medium
134773	Debian DSA-4643-1 : python-bleach - security update	Nessus	Debian Local Security Checks	medium

Detections

Analytics

CVE-2020-6816

medium

Tenable Plugins

medium

medium

medium