NSEC3 must be used for all internal DNS zones.
An XCCDF Rule
Description
<VulnDiscussion>NSEC records list the resource record types for the name, as well as the name of the next resource record. This information reveals that the resource record type for the name queried, or the resource record name requested, does not exist. NSEC uses the actual resource record names, whereas NSEC3 uses a one-way hash of the name. In this way, walking zone data from one record to the next is prevented at the expense of some CPU cycles on the authoritative server and the resolver. To prevent giving access to an entire zone file, NSEC3 should be configured. To use NSEC3, RSA/SHA-1 should be used as the algorithm, as some resolvers that understand RSA/SHA-1 might not understand NSEC3. Using RSA/SHA-256 is a safe alternative.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-259346r945250_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Log on to the DNS server using the Domain Admin or Enterprise Admin account or Local Administrator account.
If not automatically started, initialize the Server Manager window by clicking its icon from the bottom left corner of the screen.
Once the Server Manager window is initialized, from the left pane, click to select the DNS category.