HTML Cleaner allows crafted and SVG embedded scripts to pass through
CVE-2021-43818

8.2HIGH

Key Information:

Vendor

Lxml

Status
Lxml
Vendor
CVE Published:
13 December 2021

What is CVE-2021-43818?

lxml is a library for processing XML and HTML in the Python language. Prior to version 4.6.5, the HTML Cleaner in lxml.html lets certain crafted script content pass through, as well as script content in SVG files embedded using data URIs. Users that employ the HTML cleaner in a security relevant context should upgrade to lxml 4.6.5 to receive a patch. There are no known workarounds available.

Affected Version(s)

lxml < 4.6.5

References

https://github.com/lxml/lxml/security/advisories/GHSA-55x...
x_refsource_CONFIRM
https://github.com/lxml/lxml/commit/12fa9669007180a7bb87d...
x_refsource_MISC
https://github.com/lxml/lxml/commit/a3eacbc0dcf1de1c822ec...
x_refsource_MISC

EPSS Score

5% chance of being exploited in the next 30 days.

CVSS V3.1

Score:
8.2
Severity:
HIGH
Confidentiality:
Low
Integrity:
High
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.