Disable Send Packet Redirects
ICMP Redirects are used to send routing information to other hosts. As a host itself does not act as a router (in a host only configuration), there is no need to send redirects.
[no/yes, no/yes]
An attacker could use a compromised host to send invalid ICMP redirects to other router devices in an attempt to corrupt routing and have users access a system set up by the attacker as opposed to a valid system.
Fix:
Set the net.ipv4.conf.all.send_redirects and net.ipv4.conf.default.send_redirects parameters to 0 in /etc/sysctl.conf:
net.ipv4.conf.all.send_redirects=0 net.ipv4.conf.default.send_redirects=0
Modify active kernel parameters to match:
# /sbin/sysctl -w net.ipv4.conf.all.send_redirects=0
# /sbin/sysctl -w net.ipv4.conf.default.send_redirects=0
# /sbin/sysctl -w net.ipv4.route.flush=1
oval:org.secpod.oval:def:55109
SCAP Repo OVAL Definition
2019-06-19