Unbound < 1.5.9 daemon/remote.c Diffie-Hellman Key Exchange Value Small Subgroup Confinement Attack Vulnerability

medium Nessus Plugin ID 106381

Language:

New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Synopsis

The remote name server is affected by a key confinement attack vulnerability.

Description

According to its self-reported version number, the remote Unbound DNS resolver contains a flaw in the handling of Diffie-Hellman key exchange values that can allow a remote attacker to perform a small subgroup confinement attack.

Solution

Upgrade to Unbound version 1.5.9 or later.

See Also

https://nlnetlabs.nl/projects/unbound/download/

https://www.nlnetlabs.nl/bugs-script/show_bug.cgi?id=770

https://en.wikipedia.org/wiki/Small_subgroup_confinement_attack

Plugin Details

Severity: Medium

ID: 106381

File Name: unbound_1_5_9.nasl

Version: 1.5

Type: remote

Family: DNS

Published: 1/26/2018

Updated: 11/15/2018

Dependencies: unbound_version.nasl

Configuration: Enable paranoid mode

Risk Information

CVSS v2

Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

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

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

CVSS v3

Risk Factor: Medium

Base Score: 4

Temporal Score: 3.5

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

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

Vulnerability Information

CPE: cpe:/a:unbound:unbound

Required KB Items: Settings/ParanoidReport, unbound/version

Patch Publication Date: 6/9/2016

Vulnerability Publication Date: 5/26/2016