The Windows DNS Server must be configured with the Delegation Signer (DS) Resource Records (RR) carrying the signature for the RR that contains the public key of the child zone.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-259379	WDNS-22-000051	SV-259379r961104_rule		Medium

Description
If name server replies are invalid or cannot be validated, many networking functions and communication would be adversely affected. With DNS, the presence of DS records associated with child zones informs clients of the security status of child zones. These records are crucial to the DNSSEC chain of trust model. Each parent domain's DS record is used to verify the DNSKEY record in its subdomain from the top of the DNS hierarchy down. A DNS server is an example of an information system providing name/address resolution service. Digital signatures and cryptographic keys are examples of additional artifacts. DNS resource records are examples of authoritative data. Applications other than the DNS, to map between host/service names and network addresses, must provide other means to ensure the authenticity and integrity of response data. In DNS, trust in the public key of the source is established by starting from a trusted name server and establishing the chain of trust down to the current source of response through successive verifications of signature of the public key of a child by its parent. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor. A certification path starts with the subject certificate and proceeds through several intermediate certificates up to a trusted root certificate. In DNS, a trust anchor is a DNSKEY that is placed into a validating resolver so the validator can cryptographically validate the results for a given request back to a known public key (the trust anchor). One way to indicate the security status of child subspaces is through the use of DS RRs in the DNS. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Without path validation and a chain of trust, there can be no trust that the data integrity authenticity has been maintained during a transaction.

Description

If name server replies are invalid or cannot be validated, many networking functions and communication would be adversely affected. With DNS, the presence of DS records associated with child zones informs clients of the security status of child zones. These records are crucial to the DNSSEC chain of trust model. Each parent domain's DS record is used to verify the DNSKEY record in its subdomain from the top of the DNS hierarchy down. A DNS server is an example of an information system providing name/address resolution service. Digital signatures and cryptographic keys are examples of additional artifacts. DNS resource records are examples of authoritative data. Applications other than the DNS, to map between host/service names and network addresses, must provide other means to ensure the authenticity and integrity of response data. In DNS, trust in the public key of the source is established by starting from a trusted name server and establishing the chain of trust down to the current source of response through successive verifications of signature of the public key of a child by its parent. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor. A certification path starts with the subject certificate and proceeds through several intermediate certificates up to a trusted root certificate. In DNS, a trust anchor is a DNSKEY that is placed into a validating resolver so the validator can cryptographically validate the results for a given request back to a known public key (the trust anchor). One way to indicate the security status of child subspaces is through the use of DS RRs in the DNS. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Without path validation and a chain of trust, there can be no trust that the data integrity authenticity has been maintained during a transaction.

STIG	Date
Microsoft Windows Server Domain Name System (DNS) Security Technical Implementation Guide	2024-06-14

Details

Check Text ( C-63118r945297_chk )
Note: This check is not applicable for Windows DNS Servers that host only Active Directory-integrated zones or for Windows DNS Servers on a classified network. Validate this check from the Windows DNS Server being configured/reviewed. Log on to the Windows DNS Server using the account designated as Administrator or DNS Administrator. Determine a valid host in the zone. Open the Windows PowerShell prompt on the Windows DNS Server being configured/reviewed. Issue the following command: (Replace www.zonename.mil with a FQDN of a valid host in the zone being validated. Replace ###.###.###.### with the FQDN or IP address of the Windows DNS Server hosting the signed zone.) resolve-dnsname www.zonename.mil -server ###.###.###.### -dnssecok Note: It is important to use the -server switch followed by the DNS server name/IP address. The result should show the "A" record results. In addition, the results should show QueryType: RRSIG with an expiration, date signed, signer, and signature, similar to the following: Name: www.zonename.mil QueryType: RRSIG TTL: 189 Section: Answer TypeCovered: CNAME Algorithm: 8 LabelCount: 3 OriginalTtl: 300 Expiration: 11/21/2014 10:22:28 PM Signed: 10/22/2014 10:22:28 PM Signer: zonename.mil Signature: {87, 232, 34, 134...} Name: origin-www.zonename.mil QueryType: A TTL: 201 Section: Answer IP4Address: ###.###.###.### If the results do not show the RRSIG and signature information, this is a finding.

Check Text ( C-63118r945297_chk )

Note: This check is not applicable for Windows DNS Servers that host only Active Directory-integrated zones or for Windows DNS Servers on a classified network.

Validate this check from the Windows DNS Server being configured/reviewed.

Log on to the Windows DNS Server using the account designated as Administrator or DNS Administrator.

Determine a valid host in the zone.

Open the Windows PowerShell prompt on the Windows DNS Server being configured/reviewed.

Issue the following command:
(Replace www.zonename.mil with a FQDN of a valid host in the zone being validated. Replace ###.###.###.### with the FQDN or IP address of the Windows DNS Server hosting the signed zone.)

resolve-dnsname www.zonename.mil -server ###.###.###.### -dnssecok

Note: It is important to use the -server switch followed by the DNS server name/IP address.

The result should show the "A" record results.

In addition, the results should show QueryType: RRSIG with an expiration, date signed, signer, and signature, similar to the following:

Name: www.zonename.mil
QueryType: RRSIG
TTL: 189
Section: Answer
TypeCovered: CNAME
Algorithm: 8
LabelCount: 3
OriginalTtl: 300
Expiration: 11/21/2014 10:22:28 PM
Signed: 10/22/2014 10:22:28 PM
Signer: zonename.mil
Signature: {87, 232, 34, 134...}

Name: origin-www.zonename.mil
QueryType: A
TTL: 201
Section: Answer
IP4Address: ###.###.###.###

If the results do not show the RRSIG and signature information, this is a finding.

Fix Text (F-63026r945298_fix)
Sign or re-sign the hosted zone(s) on the DNS server being validated. Log on to the Windows DNS Server using the account designated as Administrator or DNS Administrator. Press the Windows key + R and execute "dnsmgmt.msc". On the opened DNS Manager snap-in from the left pane, expand the server name for the DNS server and then expand "Forward Lookup Zones". From the expanded list, right-click to select the zone (repeat for each hosted zone), point to DNSSEC, and then click "Sign the Zone" using either approved saved parameters or approved custom parameters.

Fix Text (F-63026r945298_fix)

Sign or re-sign the hosted zone(s) on the DNS server being validated.

Log on to the Windows DNS Server using the account designated as Administrator or DNS Administrator.

Press the Windows key + R and execute "dnsmgmt.msc".

On the opened DNS Manager snap-in from the left pane, expand the server name for the DNS server and then expand "Forward Lookup Zones".

From the expanded list, right-click to select the zone (repeat for each hosted zone), point to DNSSEC, and then click "Sign the Zone" using either approved saved parameters or approved custom parameters.