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1.184 RHEL-09-253020

Information

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

GROUP ID: V-257959
RULE ID: SV-257959r991589

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-routerd 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 RHEL 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/22008

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CAT|II, CCI|CCI-000366, Rule-ID|SV-257959r991589_rule, STIG-ID|RHEL-09-253020, Vuln-ID|V-257959

Plugin: Unix

Control ID: 1d46e28d241a38fefdcd7c1be79f0834439febbb66e0f725c6cafdc8349e90e6