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Ubuntu 16.04 ESM / 18.04 LTS / 20.04 LTS : libxml2 vulnerabilities (USN-4991-1)

critical Nessus Plugin ID 150858

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Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 20.10 / 21.04 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4991-1 advisory.

 - The htmlParseTryOrFinish function in HTMLparser.c in libxml2 2.9.4 allows attackers to cause a denial of service (buffer over-read) or information disclosure. (CVE-2017-8872)

 - xmlSchemaPreRun in xmlschemas.c in libxml2 2.9.10 allows an xmlSchemaValidateStream memory leak.
 (CVE-2019-20388)

 - GNOME project libxml2 v2.9.10 has a global buffer over-read vulnerability in xmlEncodeEntitiesInternal at libxml2/entities.c. The issue has been fixed in commit 50f06b3e. (CVE-2020-24977)

 - There's a flaw in libxml2's xmllint in versions before 2.9.11. An attacker who is able to submit a crafted file to be processed by xmllint could trigger a use-after-free. The greatest impact of this flaw is to confidentiality, integrity, and availability. (CVE-2021-3516)

 - 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)

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

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-4991-1

Plugin Details

Severity: Critical

ID: 150858

File Name: ubuntu_USN-4991-1.nasl

Version: 1.7

Type: local

Agent: unix

Published: 6/17/2021

Updated: 10/16/2023

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.2

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

CVSS Score Source: CVE-2021-3517

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 8.4

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

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

CVSS Score Source: CVE-2017-8872

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:esm, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libxml2, p-cpe:/a:canonical:ubuntu_linux:libxml2-dev, p-cpe:/a:canonical:ubuntu_linux:libxml2-udeb, p-cpe:/a:canonical:ubuntu_linux:libxml2-utils, p-cpe:/a:canonical:ubuntu_linux:python-libxml2, p-cpe:/a:canonical:ubuntu_linux:python3-libxml2

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/17/2021

Vulnerability Publication Date: 5/10/2017

Reference Information

CVE: CVE-2017-8872, CVE-2019-20388, CVE-2020-24977, CVE-2021-3516, CVE-2021-3517, CVE-2021-3518, CVE-2021-3537, CVE-2021-3541

USN: 4991-1