The Juniper SRX Services Gateway Firewall must protect against known types of Denial of Service (DoS) attacks by implementing signature-based screens.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-66327	JUSX-AG-000122	SV-80817r2_rule		High

Description

If the network does not provide safeguards against DoS attacks, network resources will be unavailable to users. Installation of content filtering gateways and application layer firewalls at key boundaries in the architecture mitigates the risk of DoS attacks. These attacks can be detected by matching observed communications traffic with patterns of known attacks. Juniper SRX Firewall DoS protections can be configured by either using a Screen or within the global flow options. Screens, also known as IDS-options, block various layer 3 and 4 attacks. Screen objects are configured with various screen-specific options and then assigned to a zone. The Juniper SRX can be configured with Screens to protect against the following signature-based DoS attacks: ICMP based attacks such as ping of death, IP based attacks such as IP spoofing and teardrop, and TCP based attacks such as TCP headers and land.

STIG	Date
Juniper SRX SG ALG Security Technical Implementation Guide	2019-06-28

Details

Check Text ( C-66973r1_chk )
Run the following command to see the screen options currently configured: [edit] show security screen ids-option show security zone match "screen" If security screens are not configured or if the security zone is not configured with screen options, this is a finding.

Fix Text (F-72403r3_fix)

The following example commands configure security screens under a profile named untrust-screen. Screen options with configurable thresholds may be customized to minimize/prevent operational impact on traffic performance. [edit] set security screen ids-option Based on 800-53 requirements and vendor recommendations, the following signature-based screens are required, at a minimum, for use in DoD configurations. set security screen ids-option untrust-screen icmp ping-death set security screen ids-option untrust-screen ip bad-option set security screen ids-option untrust-screen ip record-route-option set security screen ids-option untrust-screen ip timestamp-option set security screen ids-option untrust-screen ip security-option set security screen ids-option untrust-screen ip stream-option set security screen ids-option untrust-screen ip spoofing set security screen ids-option untrust-screen ip source-route-option set security screen ids-option untrust-screen ip unknown-protocol set security screen ids-option untrust-screen ip tear-drop set security screen ids-option untrust-screen ip ipv6-extension-header hop-by-hop-header jumbo-payload-option set security screen ids-option untrust-screen ip ipv6-extension-header hop-by-hop-header router-alert-option set security screen ids-option untrust-screen ip ipv6-extension-header hop-by-hop-header quick-start-option set security screen ids-option untrust-screen ip ipv6-extension-header routing-header set security screen ids-option untrust-screen ip ipv6-extension-header fragment-header set security screen ids-option untrust-screen ip ipv6-extension-header no-next-header set security screen ids-option untrust-screen ip ipv6-extension-header shim6-header set security screen ids-option untrust-screen ip ipv6-extension-header mobility-header set security screen ids-option untrust-screen ip ipv6-malformed-header set security screen ids-option untrust-screen tcp syn-fin set security screen ids-option untrust-screen tcp fin-no-ack set security screen ids-option untrust-screen tcp tcp-no-flag set security screen ids-option untrust-screen tcp syn-frag set security screen ids-option untrust-screen tcp land To enable screen protection, the screen profile must be associated with individual security zones using the following command. Recommend assigning "untrust-screen" profile name to the default zone named "untrust". [edit] set security zone security-zone screen Example: set security zones security-zone untrust screen untrust-screen