The network element can permit inbound ICMPv6 messages Packet-too-big (type 2), Time Exceeded (type 3), Parameter Problem (type 4), Echo Reply (type 129), and Neighbor Discovery (type 135-136). Remaining ICMPv6 messages must be blocked inbound.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-14686	NET-IPV6-010	SV-40968r1_rule		Medium

Description
Scanning will usually be the major stage of an information gathering process a malicious computer attacker will launch against a targeted network. With this stage the malicious computer attacker will try to determine what the characteristics of the targeted network are. Techniques, such as host detection, service detection, network topology mapping, and operating system fingerprinting are often used. The data collected will be used to identify those Hosts (if any) that are running a network service, which may have a known vulnerability. This vulnerability may allow the malicious computer attacker to execute a remote exploit in order to gain unauthorized access to those systems. This unauthorized access may become the focal point to the whole targeted network.

Description

Scanning will usually be the major stage of an information gathering process a malicious computer attacker will launch against a targeted network. With this stage the malicious computer attacker will try to determine what the characteristics of the targeted network are. Techniques, such as host detection, service detection, network topology mapping, and operating system fingerprinting are often used. The data collected will be used to identify those Hosts (if any) that are running a network service, which may have a known vulnerability. This vulnerability may allow the malicious computer attacker to execute a remote exploit in order to gain unauthorized access to those systems. This unauthorized access may become the focal point to the whole targeted network.

STIG	Date
Perimeter Router Security Technical Implementation Guide Juniper	2018-02-27

Details

Check Text ( C-39585r1_chk )
Review the configuration and ensure only approved ICMP types and codes are permitted into the enclave. Use source and destination filtering where appropriate. Apply the ICMP fragment filter to prevent DOS. [edit firewall] family inet { filter ingress-filter { term block-frags { from { is-fragment; protocol icmp; } then { syslog; discard; } } term icmp-in-good { from { destination-address { 199.36.92.0/30; } protocol icmp; icmp-type [echo-reply source quench time-exceeded parameter problem]; } then { accept; } term icmp-PMTU-D { from { destination-address { 199.36.92.0/24; } protocol icmp; icmp-type [ unreachable ]; icmp-code [ fragmentation-needed ]; } then { accept; } } } term icmp-in-bad { from { protocol icmp; } then { syslog; discard; } } } }

Check Text ( C-39585r1_chk )

Review the configuration and ensure only approved ICMP types and codes are permitted into the enclave. Use source and destination filtering where appropriate. Apply the ICMP fragment filter to prevent DOS.

[edit firewall]
family inet {
filter ingress-filter {
term block-frags {
from {
is-fragment;
protocol icmp;
}
then {
syslog;
discard;
}
}
term icmp-in-good {
from {
destination-address {
199.36.92.0/30;
}
protocol icmp;
icmp-type [echo-reply source quench time-exceeded parameter problem];
}
then {
accept;
}
term icmp-PMTU-D {
from {
destination-address {
199.36.92.0/24;
}
protocol icmp;
icmp-type [ unreachable ];
icmp-code [ fragmentation-needed ];
}
then {
accept;
}
}
}
term icmp-in-bad {
from {
protocol icmp;
}
then {
syslog;
discard;
}
}
}
}

Fix Text (F-3051r1_fix)
The network element must be configured to include controls to block inbound exploitable ICMP traffic message types.