Amazon Linux 2 : unbound, --advisory ALAS2UNBOUND-1.17-2025-006 (ALASUNBOUND-1.17-2025-006)

high Nessus Plugin ID 274073

Synopsis

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

Description

The version of unbound installed on the remote host is prior to 1.17.0-2. It is, therefore, affected by a vulnerability as referenced in the ALAS2UNBOUND-1.17-2025-006 advisory.

NLnet Labs Unbound up to and including version 1.24.0 is vulnerable to possible domain hijack attacks.
Promiscuous NS RRSets that complement positive DNS replies in the authority section can be used to trick resolvers to update their delegation information for the zone. Usually these RRSets are used to update the resolver's knowledge of the zone's name servers. A malicious actor can exploit the possible poisonous effect by injecting NS RRSets (and possibly their respective address records) in a reply. This could be done for example by trying to spoof a packet or fragmentation attacks. Unbound would then proceed to update the NS RRSet data it already has since the new data has enough trust for it, i.e., in-zone data for the delegation point. Unbound 1.24.1 includes a fix that scrubs unsolicited NS RRSets (and their respective address records) from replies mitigating the possible poison effect. (CVE-2025-11411)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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 unbound' or or 'yum update --advisory ALAS2UNBOUND-1.17-2025-006' to update your system.

See Also

https://alas.aws.amazon.com//AL2/ALAS2UNBOUND-1.17-2025-006.html

https://alas.aws.amazon.com/faqs.html

https://explore.alas.aws.amazon.com/CVE-2025-11411.html

Plugin Details

Severity: High

ID: 274073

File Name: al2_ALASUNBOUND-1_17-2025-006.nasl

Version: 1.1

Type: local

Agent: unix

Published: 11/5/2025

Updated: 11/5/2025

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

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.2

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

CVSS Score Source: CVE-2025-11411

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.6

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

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

CVSS v4

Risk Factor: High

Base Score: 7.1

Threat Score: 4.1

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:H

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:unbound-anchor, p-cpe:/a:amazon:linux:unbound-devel, p-cpe:/a:amazon:linux:python2-unbound, p-cpe:/a:amazon:linux:unbound-debuginfo, p-cpe:/a:amazon:linux:unbound-libs, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:unbound-utils, p-cpe:/a:amazon:linux:unbound, p-cpe:/a:amazon:linux:python3-unbound

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

Exploit Ease: No known exploits are available

Patch Publication Date: 11/5/2025

Vulnerability Publication Date: 10/22/2025

Reference Information

CVE: CVE-2025-11411