Detections
Analytics

1.436 OL09-00-006032

Information

OL 9 must not send Internet Control Message Protocol (ICMP) redirects.

GROUP ID: V-271875
RULE ID: SV-271875r1092337

ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.

The ability to send ICMP redirects is only appropriate for systems acting as routers.

Solution

Configure OL 9 to not allow interfaces to perform IPv4 ICMP redirects.

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

net.ipv4.conf.all.send_redirects = 0

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

$ sudo sysctl --system

See Also

https://workbench.cisecurity.org/benchmarks/27024

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CCI|CCI-000366, Rule-ID|SV-271875r1092337_rule, STIG-ID|OL09-00-006032, Vuln-ID|V-271875

Plugin: Unix

Control ID: 0fc670e8f3ad3607bc97ac2d75fd290661f105c7df2a9a07c8cfc3594e24075b