TencentOS Server 3: python-lxml (TSSA-2022:0172)

high Nessus Plugin ID 238928

Synopsis

The remote TencentOS Server 3 host is missing one or more security updates.

Description

The version of Tencent Linux installed on the remote TencentOS Server 3 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2022:0172 advisory.

Package updates are available for TencentOS Server 3 that fix the following vulnerabilities:

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.

CVE-2021-28957:
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.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://mirrors.tencent.com/tlinux/errata/tssa-20220172.xml

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43818

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28957

Plugin Details

Severity: High

ID: 238928

File Name: tencentos_TSSA_2022_0172.nasl

Version: 1.1

Type: local

Published: 6/16/2025

Updated: 6/16/2025

Supported Sensors: Nessus

Vulnerability Information

CPE: cpe:/o:tencent:tencentos_server:3, p-cpe:/a:tencent:tencentos_server:python-lxml

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/etc/os-release, Host/TencentOS/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 11/12/2022

Vulnerability Publication Date: 11/12/2022