OL09-00-006045 - OL 9 must prevent IPv6 Internet Control Message Protocol (ICMP) redirect messages from being accepted.

Information

ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.

Solution

Configure OL 9 to prevent IPv6 ICMP redirect messages from being accepted.

Add or edit the following line in a single system configuration file in the "/etc/sysctl.d/" directory:

net.ipv6.conf.default.accept_redirects = 0

Load settings from all system configuration files with the following command:

$ sudo sysctl --system

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Oracle_Linux_9_V1R4_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CAT|II, CCI|CCI-000366, Rule-ID|SV-271882r1092358_rule, STIG-ID|OL09-00-006045, Vuln-ID|V-271882

Plugin: Unix

Control ID: dab8b9c90991114a88f8f96a265a0a8c6f4733f90db9ba1a09b18cb94a17047a