Title

The IAO will ensure the Server Farm infrastructure is secured by ACLs on VLAN interfaces that restrict data originating from one server farm segment destined to another server farm segment. (Cat II impact)

Discussion

ACLs on VLAN interfaces do not protect against compromised servers. The Server farm vlans need to protect the servers located on one subnet from servers located on another subnet. Protecting a client’s data from other clients is necessary and can be accomplished using VLAN provisioning, layer 3 filtering and content filtering at the Server Farm entry point. Restricting protocol, source and destination traffic via filters is an option; however additional security practices such as content filtering are required. The Server farm private vlans need to protect the servers located on one subnet from servers located on another subnet.

Check Content

Review the firewall protecting the server farm. Vlan configurations should have a filter that secures the servers located on the vlan segment. Identify the source ip addresses that have access to the servers and verify the privilege intended with the SA. The filter should be in a deny by default posture. If the filter is not defined on the firewall and the architecture contains a layer 3 switch between the firewall and the server, than review the VLAN definition on the L3 switch.

Fix Text

Review the filter and ensure access from other server segments is denied unless necessary for application operation. The intent of the policy should be to protect servers from a server that has been compromised by an intruder.

Additional Identifiers

Rule ID:

Vulnerability ID: V-18523

Group Title:

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.