How do I install the Cis Bind9 V301 7 1 skill?

Run npx skillmds@latest add cyberstrikeus/cis-bind9-v301-7-1 in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Cis Bind9 V301 7 1 skill do?

Do Not Define a Static Source Port (Scored) It is listed under Coding & Dev Tools on SkillMD.

Is Cis Bind9 V301 7 1 safe to use?

SkillMD's automated safety review verdict for this skill is PASS. Independent scanners report: SkillSpector: PASS, Skill Scanner: PASS. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Cis Bind9 V301 7 1?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Cis Bind9 V301 7 1 free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Cis Bind9 V301 7 1?

cyberstrikeus (@cyberstrikeus) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Cis Bind9 V301 7 1 by cyberstrikeus

Name: Cis Bind9 V301 7 1
Author: cyberstrikeus

File contents

CIS 7.1 — Do Not Define a Static Source Port

Profile Applicability

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

Description

BIND can be configured to always use the same source port when communicating with other DNS servers. This capability is made possible through the query-source port option, and the query-source-v6 port option. It is recommended that the source port be omitted if the query-source option is used, or that the port be specified as a *, so that the port will not be a static port number.

Rationale

DNS attacks which involve spoofing a bogus DNS reply may require the attacker to guess the source port number of the request, if the attacker is unable to see the initial DNS query. Making the source port static makes the attack easier, as it eliminates the effort of getting the correct destination port number for the spoofed reply. Instead of a static source port, the port number should be selected randomly amount the client ephemeral ports.

Impact

None noted.

Audit Procedure

Verify that a static port is not specified in a query-source option or a query-source-v6 option, using the command below.

$ egrep '^\w*query-source' $CONFIG_FILES | grep port
/etc/named.conf:    query-source address 10.1.45.53 port *;

If there is no output from the grep or if the port number is specified as *, then the configuration is compliant. Examples of a non-compliant configurations are shown below.

query-source port 1053;

query-source port-v6 53;

Remediation

Either remove the port specification from the query-source or the query-source-v6 option or use an * for the port number.

Default Value

The default is to not use a static source port for queries.

References

None listed.

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

MITRE ATT&CK Mappings

Tactic	Technique
Initial Access	T1557 - Adversary-in-the-Middle
Credential Access	T1557.002 - ARP Cache Poisoning

Profile

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

---name: cis-bind9-v301-7-1description: Do Not Define a Static Source Port (Scored)---# CIS 7.1 — Do Not Define a Static Source Port## Profile Applicability- Level 1 - Authoritative Name Server- Level 1 - Caching Only Name Server## DescriptionBIND can be configured to always use the same source port when communicating with other DNS servers. This capability is made possible through the `query-source` port option, and the `query-source-v6` port option. It is recommended that the source port be omitted if the `query-source` option is used, or that the port be specified as a `*`, so that the port will not be a static port number.## RationaleDNS attacks which involve spoofing a bogus DNS reply may require the attacker to guess the source port number of the request, if the attacker is unable to see the initial DNS query. Making the source port static makes the attack easier, as it eliminates the effort of getting the correct destination port number for the spoofed reply. Instead of a static source port, the port number should be selected randomly amount the client ephemeral ports.## ImpactNone noted.## Audit ProcedureVerify that a static port is not specified in a query-source option or a `query-source-v6` option, using the command below.```bash$ egrep '^\w*query-source' $CONFIG_FILES | grep port/etc/named.conf: query-source address 10.1.45.53 port *;```If there is no output from the grep or if the port number is specified as `*`, then the configuration is compliant. Examples of a non-compliant configurations are shown below.```query-source port 1053;query-source port-v6 53;```## RemediationEither remove the port specification from the `query-source` or the `query-source-v6` option or use an `*` for the port number.## Default ValueThe default is to not use a static source port for queries.## ReferencesNone listed.## 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 |## MITRE ATT&CK Mappings| Tactic | Technique || ----------------- | ------------------------------- || Initial Access | T1557 - Adversary-in-the-Middle || Credential Access | T1557.002 - ARP Cache Poisoning |## Profile- Level 1 - Authoritative Name Server- Level 1 - Caching Only Name Server

Frequently asked questions

Cis Bind9 V301 7 1