The Juniper router must be configured to have Internet Control Message Protocol (ICMP) unreachable notifications disabled on all external interfaces.
An XCCDF Rule
Description
<VulnDiscussion>The ICMP supports IP traffic by relaying information about paths, routes, and network conditions. Routers automatically send ICMP messages under a wide variety of conditions. Host unreachable ICMP messages are commonly used by attackers for network mapping and diagnosis.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-254034r844135_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Disable ICMP unreachable notifications on all external interfaces.
set policy-options prefix-list router-addresses-ipv4 <external interface address>/32
set policy-options prefix-list router-addresses-ipv4 <internal subnet>/<mask>
set firewall family inet filter <name> term 1 from source-prefix-list router-address-ipv4