The Photon operating system must not send IPv4 Internet Control Message Protocol (ICMP) redirects.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258890	PHTN-40-000227	SV-258890r933731_rule		Medium

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.

STIG	Date
VMware vSphere 8.0 vCenter Appliance Photon OS 4.0 Security Technical Implementation Guide	2023-10-29

Details

Check Text ( C-62630r933729_chk )
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 Text (F-62539r933730_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.