Check: CISC-RT-000170
Cisco NX OS Switch RTR STIG:
CISC-RT-000170
(in versions v2 r3 through v1 r0.1)
Title
The Cisco switch must be configured to have Internet Control Message Protocol (ICMP) unreachable messages disabled on all external interfaces. (Cat II impact)
Discussion
The ICMP supports IP traffic by relaying information about paths, routes, and network conditions. Switches automatically send ICMP messages under a wide variety of conditions. Host unreachable ICMP messages are commonly used by attackers for network mapping and diagnosis.
Check Content
Review the switch configuration to determine if it is compliant with this requirement. The ip unreachables command must not be found on any interface as shown in the example below: interface Ethernet2/7 no switchport ip address x.22.4.2/30 ip unreachables If ICMP unreachable notifications are sent from any external interfaces, this is a finding.
Fix Text
Disable ip unreachables on all external interfaces as shown below: SW1(config)# int e2/7 SW1(config-if)# no ip unreachables SW1(config-if)# end
Additional Identifiers
Rule ID: SV-221084r856637_rule
Vulnerability ID: V-221084
Group Title: SRG-NET-000362-RTR-000113
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-002385 |
The information system protects against or limits the effects of organization-defined types of denial of service attacks by employing organization-defined security safeguards. |
Controls
Number | Title |
---|---|
SC-5 |
Denial Of Service Protection |