cis-bind-v100-3-1

name	cis-bind-v100-3-1
description	Ignore Erroneous or Unwanted Queries (Automated)
category	cis-bind
version	1.0
author	cyberstrike-official
tags	["cis","bind","dns","isc-bind","bind9","restricting-queries"]
cis_id	3.1
cis_benchmark	CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0
tech_stack	["bind","isc-bind","dns","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

CIS 3.1 — Ignore Erroneous or Unwanted Queries

Profile Applicability

• Authoritative Name Server Level 1
• Caching Only Name Server Level 1

Description

BIND can be configured to ignore requests originating from specified network segments. This is accomplished by implementing the blackhole option in named.conf. It is recommended that this feature be implemented to ignore requests that originate outside of expected network segments.

Rationale

By ignoring traffic that originates from unexpected networks, the server's exposure to malicious entities is reduced.

Impact

Not specified in the PDF.

Audit Procedure

Attempt to query the server from an address that has been placed in the blackhole list. If properly configured, the query will fail.

nslookup www.google.com ns1.example.com

Remediation

Add a blackhole option for multicast and link local addresses, and all private RFC 1918 addresses that are not being used.

blackhole {
     // Private RFC 1918 addresses
     10/8; 192.168/16; 172.16/12;
     // Multicast
     224/8;
     // Link Local
     169.254/16;
};

Default Value

No networks are blackhole'd by default.

References

Not specified in the PDF.

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v6	9 Limitation and Control of Network Ports, Protocols, and Services	Y	Y	Y
v7	9 Limitation and Control of Network Ports, Protocols, and Services	Y	Y	Y

MITRE ATT&CK Mappings

Tactic	Technique
Defense Evasion	T1562 - Impair Defenses
Initial Access	T1190 - Exploit Public-Facing Application

Profile

• Level 1 - Authoritative Name Server
• Level 1 - Caching Only Name Server