Title

The Cisco ASA must be configured to generate log records containing information to establish what type of VPN events occurred. (Cat III impact)

Discussion

Without establishing what type of event occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. VPN gateways often have a separate audit log for capturing VPN status and other information about the traffic (as opposed to the log capturing administrative and configuration actions). Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Associating event types with detected events in the VPN gateway logs provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured VPN gateway.

Check Content

Review the ASA configuration to determine if VPN events are logged as shown in the example below. logging class vpn trap notifications logging class vpnc trap notifications logging class vpnfo trap notifications logging class webfo trap notifications logging class webvpn trap notifications logging class svc trap notifications Note: A logging list can be used as an alternative to using class. If the ASA is not configured to log entries containing information to establish what type of VPN events occurred, this is a finding.

Fix Text

Configure the ASA to generate logs containing information to establish what type of VPN events occurred as shown in the example below. ciscoasa(config)# logging class vpn trap notifications ciscoasa(config)# logging class vpnc trap notifications ciscoasa(config)# logging class vpnfo trap notifications ciscoasa(config)# logging class webvpn trap notifications ciscoasa(config)# logging class webfo trap notifications ciscoasa(config)# logging class svc trap notifications ciscoasa(config)# end

Additional Identifiers

Rule ID: SV-239945r666241_rule

Vulnerability ID: V-239945

Group Title: SRG-NET-000077-VPN-000280

Expert Comments

CCIs tied to check.

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