GEN003609 - The system must ignore IPv4 Internet Control Message Protocol (ICMP) redirect messages - 'net.ipv4.conf.all.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_V2R1_STIG.zip

Item Details

Category: ACCESS CONTROL, CONFIGURATION MANAGEMENT

References: 800-53|AC-4, 800-53|CM-6d., 800-53|CM-7b., CAT|II, CCI|CCI-000382, CCI|CCI-001503, CCI|CCI-001551, Rule-ID|SV-218486r603259_rule, STIG-ID|GEN003609, STIG-Legacy|SV-64203, STIG-Legacy|V-22416, Vuln-ID|V-218486

Plugin: Unix

Control ID: aaf7beeb55a14afad1fbd6eec2662737a9caf2904f178e2f4788008ca62dc589