Amazon Linux 2 : avahi (ALAS-2020-1502)

critical Nessus Plugin ID 141943


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


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 ALAS2-2020-1502 advisory.

- The Multicast DNS (mDNS) responder in Synology DiskStation Manager (DSM) before 3.1 inadvertently responds to unicast queries with source addresses that are not link-local, which allows remote attackers to cause a denial of service (traffic amplification) or obtain potentially sensitive information via port-5353 UDP packets to the Avahi component. (CVE-2015-2809)

- avahi-daemon in Avahi through 0.6.32 and 0.7 inadvertently responds to IPv6 unicast queries with source addresses that are not on-link, which allows remote attackers to cause a denial of service (traffic amplification) and may cause information leakage by obtaining potentially sensitive information from the responding device via port-5353 UDP packets. NOTE: this may overlap CVE-2015-2809. (CVE-2017-6519)

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 avahi' to update your system.

See Also

Plugin Details

Severity: Critical

ID: 141943

File Name: al2_ALAS-2020-1502.nasl

Version: 1.3

Type: local

Agent: unix

Published: 10/27/2020

Updated: 2/13/2024

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

Risk Information


Risk Factor: Medium

Score: 6.0


Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5

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

CVSS Score Source: CVE-2017-6519


Risk Factor: Critical

Base Score: 9.1

Temporal Score: 8.2

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:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:avahi, p-cpe:/a:amazon:linux:avahi-autoipd, p-cpe:/a:amazon:linux:avahi-compat-howl, p-cpe:/a:amazon:linux:avahi-compat-howl-devel, p-cpe:/a:amazon:linux:avahi-compat-libdns_sd, p-cpe:/a:amazon:linux:avahi-compat-libdns_sd-devel, p-cpe:/a:amazon:linux:avahi-debuginfo, p-cpe:/a:amazon:linux:avahi-devel, p-cpe:/a:amazon:linux:avahi-dnsconfd, p-cpe:/a:amazon:linux:avahi-glib, p-cpe:/a:amazon:linux:avahi-glib-devel, p-cpe:/a:amazon:linux:avahi-gobject, p-cpe:/a:amazon:linux:avahi-gobject-devel, p-cpe:/a:amazon:linux:avahi-libs, p-cpe:/a:amazon:linux:avahi-qt3, p-cpe:/a:amazon:linux:avahi-qt3-devel, p-cpe:/a:amazon:linux:avahi-qt4, p-cpe:/a:amazon:linux:avahi-qt4-devel, p-cpe:/a:amazon:linux:avahi-tools, p-cpe:/a:amazon:linux:avahi-ui, p-cpe:/a:amazon:linux:avahi-ui-devel, p-cpe:/a:amazon:linux:avahi-ui-gtk3, p-cpe:/a:amazon:linux:avahi-ui-tools, cpe:/o:amazon:linux:2

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: 10/22/2020

Vulnerability Publication Date: 3/3/2015

Reference Information

CVE: CVE-2015-2809, CVE-2017-6519

BID: 73683, 106782

ALAS: 2020-1502