GEN003609 - The system must ignore IPv4 Internet Control Message Protocol (ICMP) redirect messages - 'net.ipv4.conf.default.accept_redirects'

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 the system to not accept IPv4 ICMP redirect messages.
Edit /etc/sysctl.conf and add a setting for 'net.ipv4.conf.all.accept_redirects=0' and 'net.ipv4.conf.default.accept_redirects=0'.
# sysctl -p

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Oracle_Linux_5_V1R14_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT, SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|CM-6, 800-53|SC-7(12), CAT|II, CCI|CCI-001503, CCI|CCI-001551, CSCv6|9.2, Rule-ID|SV-64203r1_rule, STIG-ID|GEN003609, Vuln-ID|V-22416

Plugin: Unix

Control ID: 2055ff1027866f2f40398d9b5db784bbd7951db8e55310652b21c0ce51fdb91f