Debian dla-4365 : libunbound-dev - security update

high Nessus Plugin ID 274071

Synopsis

The remote Debian host is missing a security-related update.

Description

The remote Debian 11 host has packages installed that are affected by a vulnerability as referenced in the dla-4365 advisory.

------------------------------------------------------------------------- Debian LTS Advisory DLA-4365-1 [email protected] https://www.debian.org/lts/security/ Guilhem Moulin November 05, 2025 https://wiki.debian.org/LTS
-------------------------------------------------------------------------

Package : unbound Version : 1.13.1-1+deb11u6 CVE ID : CVE-2025-11411

Yuxiao Wu, Yunyi Zhang, Baojun Liu and Haixin Duan discovered that unbound, a validating, recursive, and caching DNS resolver, was vulnerable to cache poisoning via NS RRSet injection, which could lead to domain hijack.

Promiscuous NS RRSets that complement 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 who is able to attach such records in a reply (i.e., spoofed packet, fragmentation attack) can poison Unbound's cache for the delegation point.

The fix scrubs unsolicited NS RRSets (and their respective address records) from replies, thereby mitigating the possible poison effect.
The protection can be turned off by setting the new configuration option iter-scrub-promiscuous to no, see unbound.conf(5).

For Debian 11 bullseye, this problem has been fixed in version 1.13.1-1+deb11u6.

We recommend that you upgrade your unbound packages.

For the detailed security status of unbound please refer to its security tracker page at:
https://security-tracker.debian.org/tracker/unbound

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS Attachment:
signature.asc Description: PGP signature

Tenable has extracted the preceding description block directly from the Debian 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

Upgrade the libunbound-dev packages.

Plugin Details

Severity: High

ID: 274071

File Name: debian_DLA-4365.nasl

Version: 1.1

Type: local

Agent: unix

Family: Debian Local Security Checks

Published: 11/5/2025

Updated: 11/5/2025

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

Risk Information

VPR

Risk Factor: Low

Score: 2.9

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: cpe:/o:debian:debian_linux:11.0, p-cpe:/a:debian:debian_linux:libunbound-dev, p-cpe:/a:debian:debian_linux:unbound, p-cpe:/a:debian:debian_linux:unbound-anchor, p-cpe:/a:debian:debian_linux:unbound-host, p-cpe:/a:debian:debian_linux:libunbound8, p-cpe:/a:debian:debian_linux:python3-unbound

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

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

Detections

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