Alpine: multiple libxml2 packages, multiple py3-libxml2 packages: security update to 2.9.11-r0

high Tenable Cloud Security Plugin ID 424088

Description

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

- Possible cross-site scripting vulnerability in libxml after commit 960f0e2. (CVE-2016-3709)

- There is a flaw in the xml entity encoding functionality of libxml2 in versions before 2.9.11. An attacker
who is able to supply a crafted file to be processed by an application linked with the affected
functionality of libxml2 could trigger an out-of-bounds read. The most likely impact of this flaw is to
application availability, with some potential impact to confidentiality and integrity if an attacker is
able to use memory information to further exploit the application. (CVE-2021-3517)

- There's a flaw in libxml2 in versions before 2.9.11. An attacker who is able to submit a crafted file to
be processed by an application linked with libxml2 could trigger a use-after-free. The greatest impact
from this flaw is to confidentiality, integrity, and availability. (CVE-2021-3518)

- A vulnerability found in libxml2 in versions before 2.9.11 shows that it did not propagate errors while
parsing XML mixed content, causing a NULL dereference. If an untrusted XML document was parsed in recovery
mode and post-validated, the flaw could be used to crash the application. The highest threat from this
vulnerability is to system availability. (CVE-2021-3537)

- A flaw was found in libxml2. Exponential entity expansion attack its possible bypassing all existing
protection mechanisms and leading to denial of service. (CVE-2021-3541)

Plugin Details

Severity: High

ID: 424088

Version: Revision 1.9

Type: Local

Family: Alpine Linux Local Security Checks

Published: 4/4/2025

Updated: 1/23/2026

Supported Sensors: Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 57.82

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2021-3517

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS Score Source: CVE-2021-3518

Vulnerability Information

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 5/14/2021

Reference Information

CVE: CVE-2016-3709, CVE-2021-3517, CVE-2021-3518, CVE-2021-3537, CVE-2021-3541

Detections

Analytics