3.3.2 Ensure IPv6 redirects are not accepted - 'net.ipv6.conf.all.accept_redirects' (sysctl.conf/sysctl.d)

Information

This setting prevents the system from accepting ICMP redirects. ICMP redirects tell the system about alternate routes for sending traffic. It is recommended that systems not accept ICMP redirects as they could be tricked into routing traffic to compromised machines. Setting hard routes within the system (usually a single default route to a trusted router) protects the system from bad routes.

Solution

Set the following parameters in the /etc/sysctl.conf file: net.ipv6.conf.all.accept_redirects = 0net.ipv6.conf.default.accept_redirects = 0 Run the following commands to set the active kernel parameters: # sysctl -w net.ipv6.conf.all.accept_redirects=0# sysctl -w net.ipv6.conf.default.accept_redirects=0# sysctl -w net.ipv6.route.flush=1

See Also

https://workbench.cisecurity.org/files/1866

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(12), CSCv6|11

Plugin: Unix

Control ID: d9394d58ec682e72413e29d8575bb88d9376328756a820301c4212211a0ec389