STIGQter STIGQter: STIG Summary: Juniper EX Series Switches Router Security Technical Implementation Guide Version: 2 Release: 1 Benchmark Date: 24 Jul 2024:

The Juniper perimeter router must be configured to protect an enclave connected to an alternate gateway by using an inbound filter that only permits packets with destination addresses within the site's address space.

DISA Rule

SV-253989r997520_rule

Vulnerability Number

V-253989

Group Title

SRG-NET-000019-RTR-000008

Rule Version

JUEX-RT-000170

Severity

CAT I

CCI(s)

Weight

10

Fix Recommendation

This requirement is not applicable for the DODIN Backbone.

Configure the ingress filter of the perimeter router connected to an alternate gateway to only permit packets with destination addresses of the site's NIPRNet address space or a destination address belonging to the address block assigned by the alternate gateway network service provider. For example:

set policy-options prefix-list inside_addresses-ipv4 <IPv4 subnet / mask>
set policy-options prefix-list inside_addresses-ipv6 <IPv6 subnet / prefix>

set firewall family inet filter inbound-ipv4 <deny terms>
set firewall family inet filter inbound-ipv4 <permit term> from <match conditions>
set firewall family inet filter inbound-ipv4 <permit term> from destination-prefix-list inside_addresses-ipv4
set firewall family inet filter inbound-ipv4 <permit term> then accept

set firewall family inet6 filter inbound-ipv6 <deny terms>
set firewall family inet6 filter inbound-ipv6 <permit term> from <match conditions>
set firewall family inet6 filter inbound-ipv6 <permit term> from destination-prefix-list inside_addresses-ipv6
set firewall family inet6 filter inbound-ipv6 <permit term> then accept

Check Contents

This requirement is not applicable for the DODIN Backbone.

Review the configuration of each router interface connecting to an alternate gateway.

Verify each permit statement of the ingress filter only permits packets with destination addresses of the site's NIPRNet address space or a destination address belonging to the address block assigned by the alternate gateway network service provider. Verify each permit statement "from" stanza (filter match conditions) references either the "destination-address" or "destination-prefix-list" directive. Using prefix lists makes management easier because managing interior addresses must only be configured in one location (the prefix-list) vice many locations (each permitting filter term). For example:
[edit policy-options]
prefix-list inside_addresses-ipv4 {
<IPv4 subnet / mask>;
}
prefix-list inside_addresses-ipv6 {
<IPv6 subnet / prefix>;
}
[edit firewall]
family inet {
filter inbound-ipv4 {
<deny terms>;
permit-term1 {
from {
<match conditions>;
destination-prefix-list inside_addresses-ipv4;
}
then accept;
}
<additional permit terms with a destination address definition>
}
}
family inet6 {
filter inbound-ipv6 {
<deny terms>;
permit-term1 {
from {
<match conditions>;
destination-prefix-list inside_addresses-ipv6;
}
then accept;
}
<additional permit terms with a destination address definition>
}
}

Verify the filter is applied inbound on exterior-facing interfaces. For example:
[edit interfaces]
<interface name> {
unit <number> {
family inet {
filter {
input inbound-ipv4;
}
address <IPv4 address / mask>;
}
family inet6 {
filter {
input inbound-ipv6;
}
address <IPv6 address / prefix>;
}
}
}

Note: Some Juniper devices support both monolithic filters and filter lists. Filter lists separate each term, or set of terms, into a separate filter that is applied sequentially to an interface. If using filter lists, the keywords "input" or "output" change to "input-list" or "output-list". Verify the final list item is a deny-all filter.

If the ingress filter permits packets with addresses other than those specified, such as destination addresses of the site's NIPRNet address space or a destination address belonging to the address block assigned by the alternate gateway network service provider, this is a finding.

Vulnerability Number

V-253989

Documentable

False

Rule Version

JUEX-RT-000170

Severity Override Guidance

This requirement is not applicable for the DODIN Backbone.

Review the configuration of each router interface connecting to an alternate gateway.

Verify each permit statement of the ingress filter only permits packets with destination addresses of the site's NIPRNet address space or a destination address belonging to the address block assigned by the alternate gateway network service provider. Verify each permit statement "from" stanza (filter match conditions) references either the "destination-address" or "destination-prefix-list" directive. Using prefix lists makes management easier because managing interior addresses must only be configured in one location (the prefix-list) vice many locations (each permitting filter term). For example:
[edit policy-options]
prefix-list inside_addresses-ipv4 {
<IPv4 subnet / mask>;
}
prefix-list inside_addresses-ipv6 {
<IPv6 subnet / prefix>;
}
[edit firewall]
family inet {
filter inbound-ipv4 {
<deny terms>;
permit-term1 {
from {
<match conditions>;
destination-prefix-list inside_addresses-ipv4;
}
then accept;
}
<additional permit terms with a destination address definition>
}
}
family inet6 {
filter inbound-ipv6 {
<deny terms>;
permit-term1 {
from {
<match conditions>;
destination-prefix-list inside_addresses-ipv6;
}
then accept;
}
<additional permit terms with a destination address definition>
}
}

Verify the filter is applied inbound on exterior-facing interfaces. For example:
[edit interfaces]
<interface name> {
unit <number> {
family inet {
filter {
input inbound-ipv4;
}
address <IPv4 address / mask>;
}
family inet6 {
filter {
input inbound-ipv6;
}
address <IPv6 address / prefix>;
}
}
}

Note: Some Juniper devices support both monolithic filters and filter lists. Filter lists separate each term, or set of terms, into a separate filter that is applied sequentially to an interface. If using filter lists, the keywords "input" or "output" change to "input-list" or "output-list". Verify the final list item is a deny-all filter.

If the ingress filter permits packets with addresses other than those specified, such as destination addresses of the site's NIPRNet address space or a destination address belonging to the address block assigned by the alternate gateway network service provider, this is a finding.

Check Content Reference

M

Target Key

5479