STIGQter: STIG Summary: Cisco IOS XE Router RTR Security Technical Implementation Guide Version: 2 Release: 2 Benchmark Date: 23 Apr 2021:

The Cisco perimeter router must be configured to block all outbound management traffic.

DISA Rule

SV-216677r531086_rule

Vulnerability Number

V-216677

Group Title

SRG-NET-000364-RTR-000113

Rule Version

CISC-RT-000390

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

This requirement is not applicable for the DODIN Backbone.

Configure the perimeter router of the managed network with an outbound ACL on the egress interface to block all management traffic.

Step 1: Configure an ACL to block egress management traffic.

R5(config)#ip access-list extended EXTERNAL_ACL_OUTBOUND
R5(config-ext-nacl)#deny tcp any any eq tacacs log-input
R5(config-ext-nacl)#deny tcp any any eq 22 log-input
R5(config-ext-nacl)#deny udp any any eq snmp log-input
R5(config-ext-nacl)#deny udp any any eq snmptrap log-input
R5(config-ext-nacl)#deny udp any any eq syslog log-input
R5(config-ext-nacl)#permit tcp any any eq www
R5(config-ext-nacl)#deny ip any any log-input
R5(config-ext-nacl)#exit

Note: Permit commands would be configured to allow applicable outbound traffic. The example above is allowing web traffic.

Step 2: Configure the external interfaces with the outbound ACL.

R1(config)#int g0/2
R1(config-if)#ip access-group EXTERNAL_ACL_OUTBOUND out

Check Contents

This requirement is not applicable for the DODIN Backbone.

The perimeter router of the managed network must be configured with an outbound ACL on the egress interface to block all management traffic as shown in the example below:

Step 1: Verify that all external interfaces has been configured with an outbound ACL as shown in the example below:

interface GigabitEthernet0/2
description link to DISN
ip address x.11.1.2 255.255.255.254
ip access-group EXTERNAL_ACL_OUTBOUND out

Step 2: Verify that the outbound ACL discards management traffic as shown in the example below:

ip access-list extended EXTERNAL_ACL_OUTBOUND
deny tcp any any eq tacacs log-input
deny tcp any any eq 22 log-input
deny udp any any eq snmp log-input
deny udp any any eq snmptrap log-input
deny udp any any eq syslog log-input
permit tcp any any eq www log-input
deny ip any any log-input

If management traffic is not blocked at the perimeter, this is a finding.

Vulnerability Number

V-216677

Documentable

False

Rule Version

CISC-RT-000390

Severity Override Guidance

This requirement is not applicable for the DODIN Backbone.

The perimeter router of the managed network must be configured with an outbound ACL on the egress interface to block all management traffic as shown in the example below:

Step 1: Verify that all external interfaces has been configured with an outbound ACL as shown in the example below:

interface GigabitEthernet0/2
description link to DISN
ip address x.11.1.2 255.255.255.254
ip access-group EXTERNAL_ACL_OUTBOUND out

Step 2: Verify that the outbound ACL discards management traffic as shown in the example below:

ip access-list extended EXTERNAL_ACL_OUTBOUND
deny tcp any any eq tacacs log-input
deny tcp any any eq 22 log-input
deny udp any any eq snmp log-input
deny udp any any eq snmptrap log-input
deny udp any any eq syslog log-input
permit tcp any any eq www log-input
deny ip any any log-input

If management traffic is not blocked at the perimeter, this is a finding.

Check Content Reference

M

Target Key

4028

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