The Juniper router must be configured to have all inactive interfaces disabled.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-253988	JUEX-RT-000160	SV-253988r843997_rule		Low

Description
An inactive interface is rarely monitored or controlled and may expose a network to an undetected attack on that interface. Unauthorized personnel with access to the communication facility could gain access to a router by connecting to a configured interface that is not in use. If an interface is no longer used, the configuration must be deleted and the interface disabled. For logical interfaces, delete those that are on inactive interfaces and delete logical interfaces that are themselves inactive. If the logical interface is no longer necessary for authorized communications, it must be deleted.

Description

An inactive interface is rarely monitored or controlled and may expose a network to an undetected attack on that interface. Unauthorized personnel with access to the communication facility could gain access to a router by connecting to a configured interface that is not in use. If an interface is no longer used, the configuration must be deleted and the interface disabled. For logical interfaces, delete those that are on inactive interfaces and delete logical interfaces that are themselves inactive. If the logical interface is no longer necessary for authorized communications, it must be deleted.

STIG	Date
Juniper EX Series Switches Router Security Technical Implementation Guide	2023-03-23

Details

Check Text ( C-57440r843995_chk )
Review the router configuration and verify unused interfaces are not configured (implicitly disabled) or are explicitly disabled. If explicitly disabling interfaces, verify multiple interfaces are disabled with the "interface-range" command or separately at each interface declaration. [edit interfaces] interface-range DISABLED_INTERFACES { member ; member-range to ; disable; } { disable; } Note: Individually disabled interfaces should not be included in any "interface-range" stanza. The "member-range" directive assigns the configured parameter(s) to contiguously numbered interfaces. Junos lists interfaces in order so a "missing" interface is not enabled. For instance, if ge-0/0/0 and ge-0/0/2 are configured, but there is no individual ge-0/0/1 stanza and that interface is not a member of an interface-range, then ge-0/0/1 is implicitly disabled. If an interface is not being used but is configured or enabled, this is a finding.

Check Text ( C-57440r843995_chk )

Review the router configuration and verify unused interfaces are not configured (implicitly disabled) or are explicitly disabled. If explicitly disabling interfaces, verify multiple interfaces are disabled with the "interface-range" command or separately at each interface declaration.

[edit interfaces]
interface-range DISABLED_INTERFACES {
member ;
member-range to ;
disable;
}
{
disable;
}

Note: Individually disabled interfaces should not be included in any "interface-range" stanza. The "member-range" directive assigns the configured parameter(s) to contiguously numbered interfaces.

Junos lists interfaces in order so a "missing" interface is not enabled. For instance, if ge-0/0/0 and ge-0/0/2 are configured, but there is no individual ge-0/0/1 stanza and that interface is not a member of an interface-range, then ge-0/0/1 is implicitly disabled.

If an interface is not being used but is configured or enabled, this is a finding.

Fix Text (F-57391r843996_fix)
Disable inactive interfaces. delete interfaces -or- set interfaces disable -or- set interfaces interface-range DISABLED_INTERFACES member set interfaces interface-range DISABLED_INTERFACES member-range to set interfaces interface-range DISABLED_INTERFACES disable