A deny-by-default ACL is not implemented on the VVoIP Signaling Gateway (SG)VLAN interface(s) on the VVoIP routing device(s) supporting the VVoIP system core (as defined in the VVoIP system ACL design) to properly control VVoIP LSC access and traffic flow.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-19639	VVoIP 5620 (LAN)	SV-21780r1_rule		Medium

Description
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 / 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 VLAN(s) to the endpoint or media gateway VLAN(s). The primary purpose of ACL on all VVoIP VLAN interface(s) is to block traffic to/from the data VLAN interface(s). 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.

Description

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 / 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 VLAN(s) to the endpoint or media gateway VLAN(s). The primary purpose of ACL on all VVoIP VLAN interface(s) is to block traffic to/from the data VLAN interface(s). 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.

STIG	Date
VOICE and VIDEO over INTERNET PROTOCOL (VVoIP) POLICY SECURITY TECHNICAL IMPLEMENTATION GUIDE	2010-08-17

Details

Check Text ( C-23973r1_chk )
Interview the IAO to obtain the required information (VVoIP system ACL Design) to determine compliance with the requirement in the next step adjusted for the actual system design. NOTE This requirement addresses the following VLANs at all routing devices supporting the VVoIP system core: SG > Signaling gateways (SG) to the DSN.

Fix Text (F-20343r1_fix)
Ensure a deny-by-default ACL is implemented on the VVoIP Signaling Gateway (SG) VLAN interface(s) on the VVoIP routing devices supporting the VVoIP system core equipment directly to control traffic as follows: > Permit (only as required for proper functionality) the specific system required signaling protocol(s) used by the Signaling Gateway ((e.g., MGCP, H.248, H.323, AS-SIP) to/from the VVoIP core control equipment VLAN interface(s) (VLAN/subnet(s)) > Deny all other traffic. End the ACL with a “deny all” statement. This is a finding in the event an ACL is not implemented generally as defined above but which may be or is adjusted for the specific VVoIP system design and protocols used.

Fix Text (F-20343r1_fix)

Ensure a deny-by-default ACL is implemented on the VVoIP Signaling Gateway (SG) VLAN interface(s) on the VVoIP routing devices supporting the VVoIP system core equipment directly to control traffic as follows:
> Permit (only as required for proper functionality) the specific system required signaling protocol(s) used by the Signaling Gateway ((e.g., MGCP, H.248, H.323, AS-SIP) to/from the VVoIP core control equipment VLAN interface(s) (VLAN/subnet(s))
> Deny all other traffic. End the ACL with a “deny all” statement.

This is a finding in the event an ACL is not implemented generally as defined above but which may be or is adjusted for the specific VVoIP system design and protocols used.