Title

A deny-by-default ACL for system management VLAN interfaces must be implemented on VVoIP core routing devices as defined in the VVoIP system ACL design. (Cat II impact)

Discussion

Router ACLs are required to control access and the flow of traffic to and from VVoIP system devices and their VLANs as a protection mechanism. In general, the defined ACLs are designed in a deny-by-default manner such that only the protocols and traffic that needs to reach the device or devices in the VLAN receive the packets. The ACLs filter on VLAN, IP address and subnet, protocol type, and associated standard IP port for the protocol. In general, the ACLs mentioned are egress filters (referenced the router core) on the VLAN interfaces. Additionally, the routing devices should log and alarm on inappropriate traffic. An example of this is an HTTP request sourced from the data VLANs to the endpoint or media gateway VLANs. The primary purpose of ACL on all VVoIP VLAN interfaces is to block traffic to or from the data VLAN interfaces. Similar restrictions are placed on a dedicated VTC VLAN interface, however, VVoIP media and signaling is permitted in the event a VTC unit needs to communicate with the UC system.

Check Content

Review site documentation, especially the VVoIP system ACL design, to confirm a deny-by-default ACL for system management VLAN interfaces is implemented on VVoIP core routing devices. Ensure a deny-by-default ACL is implemented on the VVoIP system management VLAN interfaces on the VVoIP routing devices supporting the VVoIP system core equipment to control traffic as follows: - Deny access to the VVoIP system management VLAN from the VVoIP endpoint and core equipment production VLANs - Deny access to the VVoIP system management VLAN from the general data production VLANs - Deny general access to the VVoIP system management VLAN from the general LAN management VLAN and any other management VLAN - Permit access to the VVoIP system management VLAN from other management VLANs, NOC VPNs, and enterprise management/monitoring networks as specifically required to meet mission and NETOPS requirements. Such permissions will be based on the specific IP addresses (or limited address ranges) requiring access - Permit only those ports and protocols specifically required to meet mission and NETOPS requirements If a deny-by-default ACL for system management VLAN interfaces is not implemented on VVoIP core routing devices as defined in the VVoIP system ACL design, this is a finding.

Fix Text

Implement and document a deny-by-default ACL for system management VLAN interfaces must be implemented on VVoIP core routing devices as defined in the VVoIP system ACL design as follows: - Deny access to the VVoIP system management VLAN from the VVoIP endpoint and core equipment production VLANs - Deny access to the VVoIP system management VLAN from the general data production VLANs - Deny general access to the VVoIP system management VLAN from the general LAN management VLAN and any other management VLAN - Permit access to the VVoIP system management VLAN from other management VLANs, NOC VPNs, and enterprise management/monitoring networks as specifically required to meet mission and NETOPS requirements. Such permissions will be based on the specific IP addresses (or limited address ranges) requiring access - Permit only those ports and protocols specifically required to meet mission and NETOPS requirements

Additional Identifiers

Rule ID: SV-21785r3_rule

Vulnerability ID: V-19644

Group Title: VVoIP 5645

Expert Comments

CCIs tied to check.

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