The Oracle Linux operating system must use a reverse-path filter for IPv4 network traffic when possible by default.
An XCCDF Rule
Description
<VulnDiscussion>Enabling reverse path filtering drops packets with invalid source addresses received on the interface. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-221875r880642_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
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.rp_filter = 1
Issue the following command to make the changes take effect: