Amazon Linux AMI : libxslt (ALAS-2021-1463)

critical Nessus Plugin ID 145004


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


The version of libxslt installed on the remote host is prior to 1.1.28-6.15. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS-2021-1463 advisory.

- libxslt through 1.1.33 allows bypass of a protection mechanism because callers of xsltCheckRead and xsltCheckWrite permit access even upon receiving a -1 error code. xsltCheckRead can return -1 for a crafted URL that is not actually invalid and is subsequently loaded. (CVE-2019-11068)

- In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclosed. (CVE-2019-18197)

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


Run 'yum update libxslt' to update your system.

See Also

Plugin Details

Severity: Critical

ID: 145004

File Name: ala_ALAS-2021-1463.nasl

Version: 1.2

Type: local

Agent: unix

Published: 1/14/2021

Updated: 1/14/2021

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

Risk Information

CVSS Score Source: CVE-2019-11068


Risk Factor: Medium

Score: 6.7


Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

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

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


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:libxslt, p-cpe:/a:amazon:linux:libxslt-debuginfo, p-cpe:/a:amazon:linux:libxslt-devel, p-cpe:/a:amazon:linux:libxslt-python26, p-cpe:/a:amazon:linux:libxslt-python27, cpe:/o:amazon:linux

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

Exploit Ease: No known exploits are available

Patch Publication Date: 1/12/2021

Vulnerability Publication Date: 4/10/2019

Reference Information

CVE: CVE-2019-11068, CVE-2019-18197

ALAS: 2021-1463