STIGQter: STIG Summary: Cisco IOS XR Router RTR Security Technical Implementation Guide Version: 2 Release: 1 Benchmark Date: 23 Oct 2020:

The Cisco router must be configured to only permit management traffic that ingresses and egresses the out-of-band management (OOBM) interface.

DISA Rule

SV-216773r531087_rule

Vulnerability Number

V-216773

Group Title

SRG-NET-000205-RTR-000012

Rule Version

CISC-RT-000450

Severity

CAT II

CCI(s)

• CCI-001097 - The information system monitors and controls communications at the external boundary of the information system and at key internal boundaries within the system.

Weight

10

Fix Recommendation

If the management interface is not a dedicated OOBM interface, it must be configured with both an ingress and egress ACL.

Step 1: Configure an ingress ACL a shown in the example below.

RP/0/0/CPU0:R2(config)#Ipv4 access-list INGRESS_MANAGEMENT_ACL
RP/0/0/CPU0:R2(config-ipv4-acl)#permit tcp any host 10.11.1.22 eq tacacs
RP/0/0/CPU0:R2(config-ipv4-acl)#permit tcp any host 10.11.1.22 eq 22
RP/0/0/CPU0:R2(config-ipv4-acl)#permit udp any host 10.11.1.22 eq snmp
RP/0/0/CPU0:R2(config-ipv4-acl)#permit udp any host 10.11.1.22 eq snmptrap
RP/0/0/CPU0:R2(config-ipv4-acl)#permit udp any host 10.11.1.22 eq ntp
RP/0/0/CPU0:R2(config-ipv4-acl)#permit icmp any host 10.11.1.22
RP/0/0/CPU0:R2(config-ipv4-acl)#deny ip any any log-input
RP/0/0/CPU0:R2(config-ipv4-acl)#exit

Step 2: Configure an egress ACL a shown in the example below.

RP/0/0/CPU0:R2(config)#Ipv4 access-list EGRESS_MANAGEMENT_ACL
RP/0/0/CPU0:R2(config-ipv4-acl)#deny ip any any log-input
RP/0/0/CPU0:R2(config-ipv4-acl)#exit

Step 3: Apply the ACLs to the OOBM interfaces.

RP/0/0/CPU0:R2(config)#int MgmtEth0/0/CPU0/0
RP/0/0/CPU0:R2(config-if)#ipv4 access-group INGRESS_MANAGEMENT_ACL ingress
RP/0/0/CPU0:R2(config-if)#ipv4 access-group EGRESS_MANAGEMENT_ACL egress

Check Contents

This requirement is only applicable where management access to the router is via an OOBM interface which is not a true OOBM interface.

Step 1: Verify that the managed interface has an inbound and outbound ACL configured.

interface MgmtEth0/0/CPU0/0
ipv4 address 10.1.13.4 255.255.255.0
ipv4 access-group INGRESS_MANAGEMENT_ACL ingress
ipv4 access-group EGRESS_MANAGEMENT_ACL egress

Step 2: Verify that the ingress ACL only allows management and ICMP traffic.

ipv4 access-list INGRESS_MANAGEMENT_ACL
10 permit tcp any host 10.11.1.22 eq tacacs
20 permit tcp any host 10.11.1.22 eq ssh
30 permit udp any host 10.11.1.22 eq snmp
40 permit udp any host 10.11.1.22 eq snmptrap
50 permit udp any host 10.11.1.22 eq ntp
60 permit icmp any host 10.11.1.22
70 deny ipv4 any any log-input

Step 3: Verify that the egress ACL blocks any transit traffic.

ipv4 access-list EGRESS_MANAGEMENT_ACL
10 deny ipv4 any any log-input

Note: On Cisco routers, local generated packets are not inspected by outgoing interface access-lists. Hence, the above configuration would simply drop any packets not generated by the router; hence, blocking any transit traffic.

If the router does not restrict traffic that ingresses and egresses the management interface, this is a finding.

Vulnerability Number

V-216773

Documentable

False

Rule Version

CISC-RT-000450

Severity Override Guidance

This requirement is only applicable where management access to the router is via an OOBM interface which is not a true OOBM interface.

Step 1: Verify that the managed interface has an inbound and outbound ACL configured.

interface MgmtEth0/0/CPU0/0
ipv4 address 10.1.13.4 255.255.255.0
ipv4 access-group INGRESS_MANAGEMENT_ACL ingress
ipv4 access-group EGRESS_MANAGEMENT_ACL egress

Step 2: Verify that the ingress ACL only allows management and ICMP traffic.

ipv4 access-list INGRESS_MANAGEMENT_ACL
10 permit tcp any host 10.11.1.22 eq tacacs
20 permit tcp any host 10.11.1.22 eq ssh
30 permit udp any host 10.11.1.22 eq snmp
40 permit udp any host 10.11.1.22 eq snmptrap
50 permit udp any host 10.11.1.22 eq ntp
60 permit icmp any host 10.11.1.22
70 deny ipv4 any any log-input

Step 3: Verify that the egress ACL blocks any transit traffic.

ipv4 access-list EGRESS_MANAGEMENT_ACL
10 deny ipv4 any any log-input

Note: On Cisco routers, local generated packets are not inspected by outgoing interface access-lists. Hence, the above configuration would simply drop any packets not generated by the router; hence, blocking any transit traffic.

If the router does not restrict traffic that ingresses and egresses the management interface, this is a finding.

Check Content Reference

M

Target Key

4029

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