cis-bind9-v301-3-1

DevOps & Security

Ignore Erroneous or Unwanted Queries (Automated)

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Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Server_Software/Bind/CIS_ISC_BIND_DNS_Server_9.9_Benchmark_v3.0.1/cis-bind9-v301-3-1/SKILL.md

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CIS 3.1 — Ignore Erroneous or Unwanted Queries

Profile Applicability

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

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 Applicable

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 Applicable

CIS Controls

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

MITRE ATT&CK Mappings

Tactic	Technique
Reconnaissance	T1590 - Gather Victim Network Information
Initial Access	T1190 - Exploit Public-Facing Application

Profile

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