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FreeBSD : Unbound -- Denial of service attack (2368755b-83f6-11ef-8d2e-a04a5edf46d9)

medium Nessus Plugin ID 208232

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Synopsis

The remote FreeBSD host is missing one or more security-related updates.

Description

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 2368755b-83f6-11ef-8d2e-a04a5edf46d9 advisory.

 NLnet labs report:
 A vulnerability has been discovered in Unbound when handling replies with very large RRsets that Unbound needs to perform name compression for.
 Malicious upstreams responses with very large RRsets can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks.
 Unbound version 1.21.1 introduces a hard limit on the number of name compression calculations it is willing to do per packet.
 Packets that need more compression will result in semi-compressed packets or truncated packets, even on TCP for huge messages, to avoid locking the CPU for long.
 This change should not affect normal DNS traffic.

Tenable has extracted the preceding description block directly from the FreeBSD 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

Update the affected packages.

See Also

https://nlnetlabs.nl/news/2024/Oct/03/unbound-1.21.1-released/

http://www.nessus.org/u?d6508a9a

Plugin Details

Severity: Medium

ID: 208232

File Name: freebsd_pkg_2368755b83f611ef8d2ea04a5edf46d9.nasl

Version: 1.2

Type: local

Published: 10/7/2024

Updated: 10/25/2024

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.2

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

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

CVSS Score Source: CVE-2024-8508

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:N/A:L

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

Vulnerability Information

CPE: cpe:/o:freebsd:freebsd, p-cpe:/a:freebsd:freebsd:unbound

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Exploit Ease: No known exploits are available

Patch Publication Date: 10/6/2024

Vulnerability Publication Date: 10/3/2024

Reference Information

CVE: CVE-2024-8508

IAVA: 2024-A-0682