The system must prevent local applications from generating source-routed packets.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22413	GEN003606	SV-46276r1_rule		Medium

Description
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures.

STIG	Date
SUSE Linux Enterprise Server v11 for System z Security Technical Implementation Guide	2018-09-19

Details

Check Text ( C-43433r1_chk )
Check the reverse source route settings for the system: # sysctl net.ipv4.conf.all.accept_source_route # sysctl net.ipv4.conf.default.accept_source_route If either setting has a value other than zero, this is a finding.

Fix Text (F-39576r1_fix)
Add the entries in /etc/sysctl.conf to disable reverse source routing: # printf "sysctl net.ipv4.conf.all.accept_source_route = 0\n" >> /etc/sysctl.conf # printf "sysctl net.ipv4.conf.default.accept_source_route = 0\n" >> /etc/sysctl.conf Activate the updated settings: # /sbin/sysctl -p /etc/sysctl.conf