Enable MAC spoof filtering

MediumLevel 1Automatedopenshift-virt

Description

Mac spoof filtering is a feature that helps prevent man - in - the - middle attacks by verifying the authenticity of MAC addresses in network packets. By checking the MAC address of incoming packets, mac - spoof filtering can help ensure that only authorized devices are able to communicate with a particular device or network. Audit: Passes when every SR-IOV network has spoofChk "on" and every bridge-type NetworkAttachmentDefinition sets macspoofchk to true (needs jq). OVN Kubernetes localnet filters MAC spoofing by default. Requires oc logged in to the cluster with read access.

How it is checked

Audit method: Shell command

shell

command -v oc >/dev/null 2>&1 || exit 1; command -v jq >/dev/null 2>&1 || exit 1; s=$(oc get sriovnetwork -A -o json 2>/dev/null || echo '{"items":[]}'); n=$(oc get network-attachment-definitions -A -o json) || exit 1; b1=$(printf '%s' "$s" | jq '[.items[]|select(.spec.spoofChk != "on")]|length'); b2=$(printf '%s' "$n" | jq '[.items[]|(.spec.config|fromjson? // {})|select(.type == "bridge")|select(.macspoofchk != true)]|length'); [ "$b1" = 0 ] && [ "$b2" = 0 ] && echo compliant || echo noncompliant

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Enable MAC-spoof filtering per the deployed networking provider instructions. Instructions for Bridge CNI and SR-IOV CNI.

Properties

Operating systems: Any
Tags: openshift-virtnetworkmac-spoofing
Reference: CIS Red Hat OpenShift Virtual Machine Extension Benchmark v1.0.0 - 4.2 Enable MAC spoof filtering

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target openshift-virt