Detections
Analytics

1.431 OL09-00-006026

Information

OL 9 must not forward IPv4 source-routed packets by default.

GROUP ID: V-271870
RULE ID: SV-271870r1092322

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.

Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It must be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router.

Solution

Configure OL 9 to not forward IPv4 source-routed packets by default.

Add or edit the following line in a single system configuration file in the "/etc/sysctl.d/" directory:

net.ipv4.conf.default.accept_source_route = 0

Load settings from all system configuration files with the following command:

$ sudo sysctl --system

See Also

https://workbench.cisecurity.org/benchmarks/27024

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CCI|CCI-000366, Rule-ID|SV-271870r1092322_rule, STIG-ID|OL09-00-006026, Vuln-ID|V-271870

Plugin: Unix

Control ID: ccbad662d43720315618fb457c2539be1169282b157415c2faf13b2ffdd0c986