RHEL 9 must ignore IPv6 Internet Control Message Protocol (ICMP) redirect messages.
An XCCDF Rule
Description
<VulnDiscussion>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-257972r991589_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Configure RHEL 9 to ignore IPv6 ICMP redirect messages.
Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory:
net.ipv6.conf.all.accept_redirects = 0