Title

The Cisco ASA must be configured to use TCP when sending log records to the central audit server. (Cat II impact)

Discussion

If the default UDP protocol is used for communication between the hosts and devices to the Central Log Server, then log records that do not reach the log server are not detected as a data loss. The use of TCP to transport log records to the log servers improves delivery reliability.

Check Content

Review the ASA configuration and verify it is configured to use TCP as shown in the example below. logging host NDM_INTERFACE 10.1.22.2 6/1514 logging permit-hostdown Note: The command "logging permit-hostdown" must also be configured to ensure that when either the syslog server is down or the log queue is full, new connections to ASA are allowed, to prevent an unintended denial of service. However, log records can be lost if the internal queue fills before restoring the connection to the log server. If the ASA is not configured to use TCP when sending log records to the central audit server, this is a finding.

Fix Text

Configure the ASA to use TCP when sending log records to the syslog server. ASA(config)# logging host NDM_INTERFACE 10.1.22.2 6/1514 ASA(config)# logging permit-hostdown

Additional Identifiers

Rule ID: SV-239858r819136_rule

Vulnerability ID: V-239858

Group Title: SRG-NET-000098-FW-000021

Expert Comments

CCIs tied to check.

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