Subject: [ASA-202012-1] python-lxml: cross-site scripting

Arch Linux Security Advisory ASA-202012-1
=========================================

Severity: Medium
Date    : 2020-12-05
CVE-ID  : CVE-2020-27783
Package : python-lxml
Type    : cross-site scripting
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1319

Summary
=======

The package python-lxml before version 4.6.2-1 is vulnerable to cross-
site scripting.

Resolution
==========

Upgrade to 4.6.2-1.

# pacman -Syu "python-lxml>=4.6.2-1"

The problem has been fixed upstream in version 4.6.2.

Workaround
==========

None.

Description
===========

A cross-site scripting vulnerability was discovered in python-lxml's
clean module before version 4.6.2. The module's parser didn't properly
imitate browsers, which caused different behaviors between the
sanitizer and the user's page. A remote attacker could exploit this
flaw to run arbitrary HTML/JS code.

Impact
======

A remote attacker might be able to run arbitrary JavaScript code.

References
==========

https://github.com/lxml/lxml/commit/a105ab8dc262ec6735977c25c13f0bdfcdec72a7
https://security.archlinux.org/CVE-2020-27783