The SUSE operating system must prevent Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirect messages from being accepted.
An XCCDF Rule
Description
<VulnDiscussion>ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-235018r622137_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Configure the SUSE operating system to not accept IPv4 ICMP redirect messages by running the following command as an administrator:
> sudo sysctl -w net.ipv4.conf.all.accept_redirects=0
If "0" is not the system's default value, add or update the following line in "/etc/sysctl.d/99-stig.conf":