Amazon Linux AMI : nginx (ALAS-2021-1507)

critical Nessus Plugin ID 150150
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The remote Amazon Linux AMI host is missing a security update.


The version of nginx installed on the remote host is prior to 1.18.0-1.43. It is, therefore, affected by a vulnerability as referenced in the ALAS-2021-1507 advisory.

- A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact. (CVE-2021-23017)

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 nginx' to update your system.

See Also

Plugin Details

Severity: Critical

ID: 150150

File Name: ala_ALAS-2021-1507.nasl

Version: 1.4

Type: local

Agent: unix

Published: 6/2/2021

Updated: 10/19/2021

Dependencies: ssh_get_info.nasl

Risk Information

CVSS Score Source: CVE-2021-23017


Risk Factor: High

Score: 8


Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

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

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


Risk Factor: Critical

Base Score: 9.4

Temporal Score: 8.4

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:nginx, p-cpe:/a:amazon:linux:nginx-all-modules, p-cpe:/a:amazon:linux:nginx-debuginfo, p-cpe:/a:amazon:linux:nginx-mod-http-geoip, p-cpe:/a:amazon:linux:nginx-mod-http-image-filter, p-cpe:/a:amazon:linux:nginx-mod-http-perl, p-cpe:/a:amazon:linux:nginx-mod-http-xslt-filter, p-cpe:/a:amazon:linux:nginx-mod-mail, p-cpe:/a:amazon:linux:nginx-mod-stream, cpe:/o:amazon:linux

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/1/2021

Vulnerability Publication Date: 5/25/2021

Reference Information

CVE: CVE-2021-23017

ALAS: 2021-1507