AAAA addresses must not be configured in a zone for hosts that are not dual stack.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-259361	SRG-APP-000516-DNS-000500	WDNS-22-000032	SV-259361r1018796_rule	2025-02-25	2

Description
DNS is only responsible for resolving a domain name to an IP address. Applications and operating systems are responsible for processing the IPv6 or IPv4 record that may be returned. A denial of service could easily be implemented for an application that is not IPv6 if the user is not running dual stack or any other systems utilizing IPv6. When the application receives an IP address in hexadecimal, it is up to the application/operating system to decide how to handle the response. Combining both IPv6 and IPv4 in a dual stack records into the same domain can lead to application problems that are beyond the scope of the DNS administrator.

Description

DNS is only responsible for resolving a domain name to an IP address. Applications and operating systems are responsible for processing the IPv6 or IPv4 record that may be returned. A denial of service could easily be implemented for an application that is not IPv6 if the user is not running dual stack or any other systems utilizing IPv6. When the application receives an IP address in hexadecimal, it is up to the application/operating system to decide how to handle the response. Combining both IPv6 and IPv4 in a dual stack records into the same domain can lead to application problems that are beyond the scope of the DNS administrator.

ℹ️ Check
Log on to the DNS server using the Domain Admin or Enterprise Admin account or Local Administrator account. 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, select each zone and examine the host record entries. The third column titled "Data" will display the IP. Determine if any contain both IPv4 and IPv6 addresses. If any hostnames contain both IPv4 and IPv6 addresses, confirm with the system administrator that the actual hosts are in a dual stack. If any zones contain hosts with both IPv4 and IPv6 addresses but are determined to be not in a dual stack, this is a finding.

ℹ️ Check

Log on to the DNS server using the Domain Admin or Enterprise Admin account or Local Administrator account. 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, select each zone and examine the host record entries. The third column titled "Data" will display the IP. Determine if any contain both IPv4 and IPv6 addresses. If any hostnames contain both IPv4 and IPv6 addresses, confirm with the system administrator that the actual hosts are in a dual stack. If any zones contain hosts with both IPv4 and IPv6 addresses but are determined to be not in a dual stack, this is a finding.

✔️ Fix
Remove any IPv6 records for hosts that are not in a dual stack configuration.