Amazon Linux 2 : expat (ALAS-2020-1513)

high Nessus Plugin ID 141963
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of tested product installed on the remote host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2020-1513 advisory.

- In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks). (CVE-2018-20843)

- In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early; a consecutive call to XML_GetCurrentLineNumber (or XML_GetCurrentColumnNumber) then resulted in a heap-based buffer over-read. (CVE-2019-15903)

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

Solution

Run 'yum update expat' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2020-1513.html

https://access.redhat.com/security/cve/CVE-2018-20843

https://access.redhat.com/security/cve/CVE-2019-15903

Plugin Details

Severity: High

ID: 141963

File Name: al2_ALAS-2020-1513.nasl

Version: 1.3

Type: local

Agent: unix

Published: 10/28/2020

Updated: 10/29/2020

Dependencies: ssh_get_info.nasl

Risk Information

CVSS Score Source: CVE-2018-20843

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:expat, p-cpe:/a:amazon:linux:expat-debuginfo, p-cpe:/a:amazon:linux:expat-devel, p-cpe:/a:amazon:linux:expat-static, cpe:/o:amazon:linux:2

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 10/22/2020

Vulnerability Publication Date: 6/24/2019

Reference Information

CVE: CVE-2018-20843, CVE-2019-15903

ALAS: 2020-1513