The Photon operating system must not send IPv4 Internet Control Message Protocol (ICMP) redirects.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-258890 | SRG-OS-000480-GPOS-00227 | PHTN-40-000227 | SV-258890r991589_rule | 2024-07-11 | 2 |
| Description |
|---|
| 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. |
| ℹ️ Check |
|---|
| At the command line, run the following command to verify ICMP send redirects are not accepted: # /sbin/sysctl -a --pattern "net.ipv4.conf.(all|default).send_redirects" Expected result: net.ipv4.conf.all.send_redirects = 0 net.ipv4.conf.default.send_redirects = 0 If the "send_redirects" kernel parameters are not set to "0", this is a finding. |
| ✔️ Fix |
|---|
| Navigate to and open: /etc/sysctl.d/zz-stig-hardening.conf Add or update the following lines: net.ipv4.conf.all.send_redirects = 0 net.ipv4.conf.default.send_redirects = 0 At the command line, run the following command to load the new configuration: # /sbin/sysctl --load /etc/sysctl.d/zz-stig-hardening.conf Note: If the file zz-stig-hardening.conf does not exist, it must be created. |