NET1021 - The network element must log all messages except debugging. - 'Debugging on'

Information

The network element must log all messages except debugging and send all log data to a syslog server.

Logging is a critical part of router security. Maintaining an audit trail of system activity logs (syslog) can help identify configuration errors, understand past intrusions, troubleshoot service disruptions, and react to probes and scans of the network. Syslog levels 0-6 are the levels required to collect the necessary information to help in the recovery process.

Cisco IOS routers and switches use level 6 (informational) when logging packets that are dropped via access control list. (%SEC-6-IPACCESSLOGNP: list 1 denied 0 1.1.1.2 -> 1.1.1.1, 1 packet). Hence, it is imperative that log messages at level 6 are captured for further analysis and incident reporting. However, these messages do not need to go to the console, but must go to the syslog server.

To avoid being locked out of the console in the event of an intensive log message generation such as when a large number of packets are being dropped, you can implement any of the following:

1. Limit the amount of logging based on same packet matching via the access-list log-update threshold command. The configured threshold specifies how often syslog messages are generated and sent after the initial packet match on a per flow basis.
2. Rate-limit messages at specific severity levels destined to be logged at the console via logging rate-limit command.
3. Have only messages at levels 0-5 (or 0-4) go to the console and messages at level 0-6 go to the syslog server.

The buffer could be set to notification level or altered to a different level when required (i.e. debugging).

Solution

Configure the network element to log all messages except debugging and send all log data to a syslog server.

See Also

https://iasecontent.disa.mil/stigs/zip/U_Network_Infrastructure_Router_L3_Switch_V8R29_STIG.zip

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-2, CAT|III, Rule-ID|SV-15476r2_rule, STIG-ID|NET1021, Vuln-ID|V-4584

Plugin: Cisco

Control ID: 32284f6c24a35b17f0b8b95ebe7d31fccb2dac9129eab7e4cfd95224e5dc46c4