Title

The DNS server implementation must authenticate another DNS server before establishing a remote and/or network connection using bidirectional authentication that is cryptographically based. (Cat II impact)

Discussion

Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Bidirectional authentication provides stronger safeguards to validate the identity of other devices for connections that are of greater risk. This requirement applies to server-to-server (zone transfer) transactions only and is provided by TSIG/SIG(0), which enforces mutual server authentication using a key that is unique to each server pair (TSIG) or using PKI-based authentication (SIG(0)).

Check Content

Navigate to Data Management >> DNS >> Zones tab. Review each zone by clicking "Edit" and inspecting the "Name Servers" tab. If the all entries in the "Type" column are configured as "Grid", this check is not applicable. Verify that each zone which contains non-Grid name servers is further verified by inspection of the "Zone Transfers" tab and configuration of TSIG Access Control Entry (ACE). If there is a non-Grid system which utilizes zone transfers but does not have a TSIG key, this is a finding. When complete, click "Cancel" to exit the "Properties" screen.

Fix Text

Navigate to Data Management >> DNS >> Zones tab. Select a zone and click "Edit". Click on "Zone Transfers" tab, and click "Override" for the "Allow Zone Transfers to" section. Use the radio button to select "Set of ACEs" and the "Add" dropdown to configure a TSIG key. It is important to verify that both the Infoblox and other DNS server have the identical TSIG configuration. When complete, click "Save & Close" to save the changes and exit the "Properties" screen. Perform a service restart if necessary. Verify zone transfers are operational after configuration of TSIG.

Additional Identifiers

Rule ID: SV-214187r612370_rule

Vulnerability ID: V-214187

Group Title: SRG-APP-000395-DNS-000050

Expert Comments

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