Detections
Analytics

1.426 OL09-00-006021

Information

OL 9 must not forward Internet Protocol version 4 (IPv4) source-routed packets.

GROUP ID: V-271865
RULE ID: SV-271865r1092307

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. 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.

Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It must be disabled unless it is absolutely required.

Solution

Configure OL 9 to ignore IPv4 source-routed packets.

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

net.ipv4.conf.all.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-271865r1092307_rule, STIG-ID|OL09-00-006021, Vuln-ID|V-271865

Plugin: Unix

Control ID: 226a888095617dfded8fb8e310f8679aa4c3b03236d90f35a37d6df98b4dcf43