CVE-2020-27783: lxml vulnerable to Cross-site Scripting

CVE-2020-27783 · Severity: low · CVSS 3.1 · Published 2020-12-03

A XSS vulnerability was discovered in python-lxml's clean module. 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.

Technologies: lxml (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2020-27783 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2020-27783 being exploited in the wild.
How severe is CVE-2020-27783?
Low severity, with a CVSS score of 3.1, published 3 December 2020.
Which products and versions are affected?
lxml (PyPI) ECOSYSTEM:introduced=0,fixed=4.6.2, ECOSYSTEM:introduced=1.2,fixed=4.6.2.
Is there a fix for CVE-2020-27783?
Yes. lxml (PyPI): upgrade to 4.6.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2020-27783?
Check whether you run lxml (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • lxml (PyPI): upgrade to 4.6.2 or later
    pip install "lxml>=4.6.2"

Affected products

  • lxml (PyPI) ECOSYSTEM:introduced=0,fixed=4.6.2, ECOSYSTEM:introduced=1.2,fixed=4.6.2

Identifiers

  • CVE-2020-27783
  • GHSA-pgww-xf46-h92r
  • PYSEC-2020-62

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