STIGQter STIGQter: STIG Summary: Juniper EX Series Switches Network Device Management Security Technical Implementation Guide Version: 2 Release: 5 Benchmark Date: 01 Jul 2026:

The Juniper EX switch must be configured to protect against known types of denial-of-service (DoS) attacks by employing organization-defined security safeguards.

DISA Rule

SV-253930r961620_rule

Vulnerability Number

V-253930

Group Title

SRG-APP-000435-NDM-000315

Rule Version

JUEX-NM-000530

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure the network device to protect against or limit the effects of all known types of DoS attacks by employing organization-defined security safeguards.

SSH example:
set system services ssh connection-limit <1..250>
set system services ssh rate-limit <1..250>

NETCONF over SSH example:
set system services netconf ssh connection-limit <1..250>
set system services netconf ssh rate-limit <1..250>

Example firewall filters:
set firewall family inet filter <filter name> term 1 from destination-address <device OOBM or loopback address>
set firewall family inet filter <filter name> term 1 from source-prefix-list <management address list name>
set firewall family inet filter <filter name> term 1 from protocol tcp
set firewall family inet filter <filter name> term 1 from destination-port 22
set firewall family inet filter <filter name> term 1 from tcp-initial
set firewall family inet filter <filter name> term 1 then policer policer-32k
set firewall family inet filter <filter name> term 1 then syslog
set firewall family inet filter <filter name> term 1 then accept
set firewall family inet filter <filter name> term 2 from destination-address <device OOBM or loopback address>
set firewall family inet filter <filter name> term 2 from source-prefix-list <management address list name>
set firewall family inet filter <filter name> term 2 from protocol tcp
set firewall family inet filter <filter name> term 2 from destination-port 22
set firewall family inet filter <filter name> term 2 then syslog
set firewall family inet filter <filter name> term 2 then accept
set firewall family inet filter <filter name> term default then syslog
set firewall family inet filter <filter name> term default then discard
set firewall family inet6 filter <filter name-1> term 1 from destination-address <device OOBM or loopback address>
set firewall family inet6 filter <filter name-1> term 1 from source-prefix-list <management address list name-1>
set firewall family inet6 filter <filter name-1> term 1 from next-header tcp
set firewall family inet6 filter <filter name-1> term 1 from destination-port 22
set firewall family inet6 filter <filter name-1> term 1 from tcp-initial
set firewall family inet6 filter <filter name-1> term 1 then policer policer-32k
set firewall family inet6 filter <filter name-1> term 1 then syslog
set firewall family inet6 filter <filter name-1> term 1 then accept
set firewall family inet6 filter <filter name-1> term 2 from destination-address <device OOBM or loopback address>
set firewall family inet6 filter <filter name-1> term 2 from source-prefix-list <management address list name-1>
set firewall family inet6 filter <filter name-1> term 2 from next-header tcp
set firewall family inet6 filter <filter name-1> term 2 from destination-port 22
set firewall family inet6 filter <filter name-1> term 2 then syslog
set firewall family inet6 filter <filter name-1> term 2 then accept
set firewall family inet6 filter <filter name-1> term default then syslog
set firewall family inet6 filter <filter name-1> term default then discard

Example interface configuration:
set interfaces <OOBM interface> unit 0 family inet filter input <filter name>
set interfaces <OOBM interface> unit 0 family inet address <IPv4 address>/<mask>
set interfaces <OOBM interface> unit 0 family inet6 filter input <filter name-1>
set interfaces <OOBM interface> unit 0 family inet6 address <IPv6 address>/<prefix>

Check Contents

Determine if the network device protects against or limits the effects of all known types of DoS attacks by employing organization-defined security safeguards.

Verify session and (if supported) rate limits for management connections.
SSH example:
[edit system services ssh]
connection-limit <1..250>;
rate-limit <1..250>;
Note: The SSH connection- and rate-limit directives affect secure file transfer protocols like SCP and SFTP.

NETCONF over SSH example:
[edit system services netconf]
ssh {
connection-limit <1..250>;
rate-limit <1..250>;
}
Note: Rate limiting is the permissible number of connections per one minute interval.

Verify policers (rate limiters) are appropriately applied to limit traffic; for example, to limit SSH connection attempts:
[edit firewall]
family inet {
filter <filter name> {
term 1 {
from {
destination-address {
<device OOBM or loopback address>;
}
source-prefix-list {
<management address list name>;
}
protocol tcp;
destination-port 22;
tcp-initial;
}
then {
policer policer-32k;
syslog;
accept;
}
}
term 2 {
from {
destination-address {
<device OOBM or loopback address>;
}
source-prefix-list {
<management address list name>;
}
protocol tcp;
destination-port 22;
}
then {
syslog;
accept;
}
}
term default {
then {
syslog;
discard;
}
}
}
}
family inet6 {
filter <filter name-1> {
term 1 {
from {
destination-address {
<device OOBM or loopback address>;
}
source-prefix-list {
<management address list name-1>;
}
next-header tcp;
destination-port 22;
tcp-initial;
}
then {
policer policer-32k;
syslog;
accept;
}
}
term 2 {
from {
destination-address {
<device OOBM or loopback address>;
}
source-prefix-list {
<management address list name-1>;
}
next-header tcp;
destination-port 22;
}
then {
syslog;
accept;
}
}
term default {
then {
syslog;
discard;
}
}
}
}
Note: Additional terms will be required for other services like SNMP.
policer policer-32k {
if-exceeding {
bandwidth-limit 32k;
burst-size-limit 1500;
}
then discard;
}

[edit interfaces]
<OOBM interface> {
unit 0 {
family inet {
filter {
input <filter name>;
}
address <IPv4 address>/<mask>;
}
family inet6 {
filter {
input <filter name-1>;
}
address <IPv6 address>/<prefix>;
}
}
}
Note: Although the example filter is shown applied to the management interface, the filter can be also be applied to the loopback interface. If applying to loopback, ensure the filter terms account for all traffic, services, and protocols that must reach the routing engine (e.g., OSPF, BGP, SNMP, etc.).

If the network device does not protect against or limit the effects of all known types of DoS attacks by employing organization-defined security safeguards, this is a finding.

Vulnerability Number

V-253930

Documentable

False

Rule Version

JUEX-NM-000530

Severity Override Guidance

Determine if the network device protects against or limits the effects of all known types of DoS attacks by employing organization-defined security safeguards.

Verify session and (if supported) rate limits for management connections.
SSH example:
[edit system services ssh]
connection-limit <1..250>;
rate-limit <1..250>;
Note: The SSH connection- and rate-limit directives affect secure file transfer protocols like SCP and SFTP.

NETCONF over SSH example:
[edit system services netconf]
ssh {
connection-limit <1..250>;
rate-limit <1..250>;
}
Note: Rate limiting is the permissible number of connections per one minute interval.

Verify policers (rate limiters) are appropriately applied to limit traffic; for example, to limit SSH connection attempts:
[edit firewall]
family inet {
filter <filter name> {
term 1 {
from {
destination-address {
<device OOBM or loopback address>;
}
source-prefix-list {
<management address list name>;
}
protocol tcp;
destination-port 22;
tcp-initial;
}
then {
policer policer-32k;
syslog;
accept;
}
}
term 2 {
from {
destination-address {
<device OOBM or loopback address>;
}
source-prefix-list {
<management address list name>;
}
protocol tcp;
destination-port 22;
}
then {
syslog;
accept;
}
}
term default {
then {
syslog;
discard;
}
}
}
}
family inet6 {
filter <filter name-1> {
term 1 {
from {
destination-address {
<device OOBM or loopback address>;
}
source-prefix-list {
<management address list name-1>;
}
next-header tcp;
destination-port 22;
tcp-initial;
}
then {
policer policer-32k;
syslog;
accept;
}
}
term 2 {
from {
destination-address {
<device OOBM or loopback address>;
}
source-prefix-list {
<management address list name-1>;
}
next-header tcp;
destination-port 22;
}
then {
syslog;
accept;
}
}
term default {
then {
syslog;
discard;
}
}
}
}
Note: Additional terms will be required for other services like SNMP.
policer policer-32k {
if-exceeding {
bandwidth-limit 32k;
burst-size-limit 1500;
}
then discard;
}

[edit interfaces]
<OOBM interface> {
unit 0 {
family inet {
filter {
input <filter name>;
}
address <IPv4 address>/<mask>;
}
family inet6 {
filter {
input <filter name-1>;
}
address <IPv6 address>/<prefix>;
}
}
}
Note: Although the example filter is shown applied to the management interface, the filter can be also be applied to the loopback interface. If applying to loopback, ensure the filter terms account for all traffic, services, and protocols that must reach the routing engine (e.g., OSPF, BGP, SNMP, etc.).

If the network device does not protect against or limit the effects of all known types of DoS attacks by employing organization-defined security safeguards, this is a finding.

Check Content Reference

M

Target Key

5477