4.620 - The system must not forward Internet Protocol version 4 (IPv4) source-routed packets by default - config

Information

Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router.

Solution

Set the system to the required kernel parameter by adding the following line to '/etc/sysctl.conf' or a configuration file in the /etc/sysctl.d/ directory (or modify the line to have the required value):

net.ipv4.conf.default.accept_source_route = 0

Issue the following command to make the changes take effect:

# sysctl --system

See Also

https://docs.fedoraproject.org/f28/system-administrators-guide/index.html

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(12), CAT|II, CCI|CCI-000366, CSCv6|9.2

Plugin: Unix

Control ID: fbc91d773f9d78d433e75e3f99dc58d908d17ace1da7be7c7ba60abd34b28bfb