Rule ID
SV-285247r1258680_rule
Version
V1R1
CCIs
A mechanism to detect and prevent unauthorized communication flow must be configured or provided as part of the system design. If information flow is not enforced based on approved authorizations, the system may become compromised. Information flow control regulates where information is allowed to travel within a system and between interconnected systems. The flow of all application information must be monitored and controlled so it does not introduce any unacceptable risk to the systems or data. Application-specific examples of enforcement occurs in systems that employ rule sets or establish configuration settings that restrict information system services or provide a message filtering capability based on message content (e.g., implementing key word searches or using document characteristics). Applications providing information flow control must be able to enforce approved authorizations for controlling the flow of information between interconnected systems in accordance with applicable policy. Within the context of DNS, this is applicable in terms of controlling the flow of DNS information between systems, such as DNS zone transfers.
Verify Infoblox DNS service members are configured to enforce approved authorizations for controlling the flow of information between DNS servers and between DNS servers and DNS clients based on DNSSEC policies. Note: If all DNS service members are within the same Infoblox Grid, this is not a finding. Review the configuration of Infoblox DNS systems and verify communication flow is validated. 1. Review the Infoblox DNS configuration to verify only approved communications are allowed. 2. Use of Access Control Lists to control clients, DNS zone transfer configuration to systems external to the Infoblox Grid, and Grid member configuration can be used to control communications as required. Note: Infoblox DNS service members within the same Grid use internal database updates and do not perform zone transfers. Zones must be assigned to a Name Server Group (NSG) and must never have the zone transfer configuration overridden as the NSG automatically configures this. If the Infoblox system is configured to perform zone transfers to non-Grid systems, and an access control method is not used, this is a finding.
Zone transfers can be restricted at the Grid, Member, and Zone level. Configuration is inherited and can be overridden if necessary to construct the appropriate access control. Refer to the Infoblox Administrator Guide if necessary. Grid-level configuration: 1. Navigate to Data Management >> DNS >> Zones tab. 2. Click "Grid DNS Properties" (Toolbar menu) and toggle "Basic Mode". 3. Click the "Zone Transfers" tab. 4. Under "Allow zone transfers to", select "None". 5. When complete, click "Save & Close". Member-level configuration: 1. Navigate to Data Management >> DNS >> Members tab. 2. Click "Edit" icon to review each member with the DNS service status of "Running". 3. Toggle "Basic Mode" and click "Zone Transfers". 4. Under "Allow zone transfers to", select "None". Zone level configuration: Zones must be assigned to an NSG and must never have the zone transfer configuration overridden, as the NSG automatically configures this.