Cross-site Scripting (XSS) Affecting py3-lxml package, versions <4.6.3-r0


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
4.03% (90th percentile)

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  • Snyk IDSNYK-ALPINE321-PY3LXML-8485593
  • published6 Dec 2024
  • disclosed21 Mar 2021

Introduced: 21 Mar 2021

CVE-2021-28957  (opens in a new tab)
CWE-79  (opens in a new tab)

How to fix?

Upgrade Alpine:3.21 py3-lxml to version 4.6.3-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream py3-lxml package and not the py3-lxml package as distributed by Alpine. See How to fix? for Alpine:3.21 relevant fixed versions and status.

An XSS vulnerability was discovered in python-lxml's clean module versions before 4.6.3. When disabling the safe_attrs_only and forms arguments, the Cleaner class does not remove the formaction attribute allowing for JS to bypass the sanitizer. A remote attacker could exploit this flaw to run arbitrary JS code on users who interact with incorrectly sanitized HTML. This issue is patched in lxml 4.6.3.

CVSS Base Scores

version 3.1