CVE-2021-28957

Description

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.

Weakness classification

• nvd@nist.gov: CWE-79
• 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-79

Primary references

• cve@mitre.org — Exploit, Issue Tracking, Third Party Advisory
• cve@mitre.org — Patch, Third Party Advisory
• cve@mitre.org — Patch, Third Party Advisory
• cve@mitre.org — Mailing List, Third Party Advisory
• cve@mitre.org
• cve@mitre.org
• cve@mitre.org — Third Party Advisory
• cve@mitre.org — Third Party Advisory
• cve@mitre.org — Third Party Advisory
• cve@mitre.org — Patch, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Exploit, Issue Tracking, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory