The Cisco IOS XE router must be configured to disable non-essential capabilities.
A compromised router introduces risk to the entire network infrastructure as well as data resources that are accessible via the network. The perimeter defense has no oversight or control of attacks by malicious users within the network. Preventing network breaches from within is dependent on implementing a comprehensive defense-in-depth strategy including securing each device connected to the network. This is accomplished by following and implementing all security guidance applicable for each node type. A fundamental step in securing each router is to enable only the capabilities required for operation.
Disable all unnecessary or non-secure ports, protocols and services. no ip bootp server no ip dns server no ip finger no ip http server no ip identd no ip rcmd rcp-enable no ip rcmd rsh-enable no service config no service udp-small-servers no service tcp-small-servers no service finger no service pad line vty 0 4 no transport input no transport output transport input ssh transport output ssh Note: transport input and output for telnet service can’t be disabled individually; hence, ssh must be reinserted for access to the line vty configuration.
Verify that the Cisco IOS XE router does not have any unnecessary or non-secure ports, protocols and services enabled. For example, the following commands should not be in the configuration: ip bootp server ip dns server ip finger ip http server ip identd ip rcmd rcp-enable ip rcmd rsh-enable service config service finger service tcp-small-servers service udp-small-servers service pad transport input telnet transport output telnet If any unnecessary or non-secure ports, protocols or services are enabled, this is a finding.