Manual ArgoCD NetworkPolicy mitigation (GHSA-47m3-95c7-g2g8)

Solutions for unauthenticated network access to the ArgoCD repo-server and Redis in Automation Suite, with a manual NetworkPolicy mitigation procedure.

Description

A vulnerability affecting the ArgoCD repo-server component was recently published and is not fixed by ArgoCD at this moment.

The ArgoCD repo-server (port 8081) and ArgoCD Redis are reachable from any pod in the cluster network, because no NetworkPolicy restricts ingress to these components by default. As a result, any pod within the cluster network can connect to them directly, since ArgoCD does not require authentication for these internal components. For details, refer to GHSA-47m3-95c7-g2g8.

To mitigate the issue, you must manually apply the NetworkPolicy described in the Solution section on this page.

Prerequisites

• Run this procedure from a host with kubectl access to the cluster.
• The procedure assumes the default Automation Suite argocd namespace. If ArgoCD uses a different namespace, set ARGOCD_NS before running the script.
• This mitigation relies on Kubernetes NetworkPolicy enforcement, which is provided by the CNI (Container Network Interface) plugin. Some CNIs, such as the Amazon VPC CNI, do not enforce network policies by default; in that case, the applied policies have no effect. Make sure network policy enforcement is enabled in your cluster. For instructions, refer to the official documentation of your CNI.

Solution

1. Run the following script. It detects your ArgoCD release and Redis mode (standalone or high availability, HA), and applies the matching NetworkPolicy automatically:

   export ARGOCD_NS="${ARGOCD_NS:-argocd}"
   export ARGOCD_RELEASE="$(kubectl -n "$ARGOCD_NS" get pod -l app.kubernetes.io/name=argocd-server -o jsonpath='{.items[0].metadata.labels.app\.kubernetes\.io/instance}')"
   
   test -n "$ARGOCD_RELEASE" || { echo "Cannot detect Argo CD Helm release"; exit 1; }
   
   if kubectl -n "$ARGOCD_NS" get pod -l "release=${ARGOCD_RELEASE},app=redis-ha-haproxy,component=haproxy" --no-headers 2>/dev/null | grep -q .; then
     REDIS_MODE=ha
   else
     REDIS_MODE=standalone
   fi
   
   echo "Argo CD namespace: $ARGOCD_NS"
   echo "Argo CD release: $ARGOCD_RELEASE"
   echo "Redis mode: $REDIS_MODE"
   
   cat <<EOF | kubectl apply -f -
   apiVersion: networking.k8s.io/v1
   kind: NetworkPolicy
   metadata:
     name: argocd-repo-server-manual-mitigation
     namespace: ${ARGOCD_NS}
   spec:
     podSelector:
       matchLabels:
         app.kubernetes.io/name: argocd-repo-server
         app.kubernetes.io/instance: ${ARGOCD_RELEASE}
     policyTypes:
       - Ingress
     ingress:
       - from:
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-server
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-application-controller
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-applicationset-controller
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-notifications-controller
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
         ports:
           - protocol: TCP
             port: 8081
       - from:
           - namespaceSelector: {}
         ports:
           - protocol: TCP
             port: 8084
   EOF
   
   if [ "$REDIS_MODE" = "ha" ]; then
     cat <<EOF | kubectl apply -f -
   apiVersion: networking.k8s.io/v1
   kind: NetworkPolicy
   metadata:
     name: argocd-redis-ha-server-manual-mitigation
     namespace: ${ARGOCD_NS}
   spec:
     podSelector:
       matchLabels:
         release: ${ARGOCD_RELEASE}
         app: redis-ha
     policyTypes:
       - Ingress
     ingress:
       - from:
           - podSelector:
               matchLabels:
                 release: ${ARGOCD_RELEASE}
                 app: redis-ha
           - podSelector:
               matchLabels:
                 release: ${ARGOCD_RELEASE}
                 app: redis-ha-haproxy
                 component: haproxy
         ports:
           - protocol: TCP
             port: 6379
           - protocol: TCP
             port: 26379
   ---
   apiVersion: networking.k8s.io/v1
   kind: NetworkPolicy
   metadata:
     name: argocd-redis-ha-haproxy-manual-mitigation
     namespace: ${ARGOCD_NS}
   spec:
     podSelector:
       matchLabels:
         release: ${ARGOCD_RELEASE}
         app: redis-ha-haproxy
         component: haproxy
         app.kubernetes.io/name: argocd-redis-ha-haproxy
     policyTypes:
       - Ingress
     ingress:
       - from:
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-server
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-repo-server
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-application-controller
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
         ports:
           - protocol: TCP
             port: 6379
   EOF
   else
     cat <<EOF | kubectl apply -f -
   apiVersion: networking.k8s.io/v1
   kind: NetworkPolicy
   metadata:
     name: argocd-redis-manual-mitigation
     namespace: ${ARGOCD_NS}
   spec:
     podSelector:
       matchLabels:
         app.kubernetes.io/name: argocd-redis
         app.kubernetes.io/instance: ${ARGOCD_RELEASE}
     policyTypes:
       - Ingress
     ingress:
       - from:
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-server
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-repo-server
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
           - podSelector:
               matchLabels:
                 app.kubernetes.io/name: argocd-application-controller
                 app.kubernetes.io/instance: ${ARGOCD_RELEASE}
         ports:
           - protocol: TCP
             port: 6379
       - from:
           - namespaceSelector: {}
         ports:
           - protocol: TCP
             port: 9121
   EOF
   fi
   

Verify

Run the following commands to confirm the mitigation was applied successfully:

kubectl -n "$ARGOCD_NS" get networkpolicy
kubectl -n "$ARGOCD_NS" get pods
kubectl get applications.argoproj.io -A

Confirm the following:

• argocd-repo-server-manual-mitigation exists.
• For Redis HA, argocd-redis-ha-server-manual-mitigation and argocd-redis-ha-haproxy-manual-mitigation exist.
• For standalone Redis, argocd-redis-manual-mitigation exists.
• ArgoCD pods are Running or Completed.
• ArgoCD Applications remain Synced and Healthy.

Confirm Mitigation

Run these checks after applying the policies. They verify that required ArgoCD traffic still works and disallowed traffic is blocked.

1. Run the following script:

   export ARGOCD_NS="${ARGOCD_NS:-argocd}"
   export ARGOCD_RELEASE="${ARGOCD_RELEASE:-$(kubectl -n "$ARGOCD_NS" get pod -l app.kubernetes.io/name=argocd-server -o jsonpath='{.items[0].metadata.labels.app\.kubernetes\.io/instance}')}"
   
   if kubectl -n "$ARGOCD_NS" get pod -l "release=${ARGOCD_RELEASE},app=redis-ha-haproxy,component=haproxy" --no-headers 2>/dev/null | grep -q .; then
     REDIS_MODE=ha
   else
     REDIS_MODE=standalone
   fi
   
   SERVER_POD="$(kubectl -n "$ARGOCD_NS" get pod -l app.kubernetes.io/name=argocd-server -o jsonpath='{.items[0].metadata.name}')"
   APPSET_POD="$(kubectl -n "$ARGOCD_NS" get pod -l app.kubernetes.io/name=argocd-applicationset-controller -o jsonpath='{.items[0].metadata.name}' 2>/dev/null || true)"
   FAILED_CHECKS=""
   
   tcp_check() {
     pod="$1"
     host="$2"
     port="$3"
     expected="$4"
     name="$5"
   
     code="$(kubectl -n "$ARGOCD_NS" exec "$pod" -- sh -c '
       host="$1"
       port="$2"
       if command -v nc >/dev/null 2>&1; then
         timeout 5 nc -z -w 3 "$host" "$port" >/dev/null 2>&1
         printf "%s\n" "$?"
       elif command -v bash >/dev/null 2>&1; then
         timeout 5 bash -c "</dev/tcp/${host}/${port}" >/dev/null 2>&1
         printf "%s\n" "$?"
       else
         printf "%s\n" "NO_TCP_TOOL"
       fi
     ' sh "$host" "$port" 2>/dev/null | tail -n 1)"
   
     if [ "$expected" = "allow" ] && [ "$code" = "0" ]; then
       return
     elif [ "$expected" = "deny" ] && [ "$code" != "0" ] && [ "$code" != "NO_TCP_TOOL" ] && [ -n "$code" ]; then
       return
     else
       FAILED_CHECKS="${FAILED_CHECKS}
   - ${name}: expected ${expected}, got exit code ${code}"
     fi
   }
   
   tcp_check "$SERVER_POD" argocd-repo-server 8081 allow "argocd-server to repo-server:8081"
   
   if [ "$REDIS_MODE" = "ha" ]; then
     HAPROXY_POD="$(kubectl -n "$ARGOCD_NS" get pod -l app=redis-ha-haproxy,component=haproxy -o jsonpath='{.items[0].metadata.name}')"
   
     tcp_check "$SERVER_POD" argocd-redis-ha-haproxy 6379 allow "argocd-server to redis-ha-haproxy:6379"
     tcp_check "$HAPROXY_POD" argocd-redis-ha 6379 allow "redis-ha-haproxy to redis-ha:6379"
     tcp_check "$HAPROXY_POD" argocd-repo-server 8081 deny "redis-ha-haproxy to repo-server:8081"
   
     if [ -n "$APPSET_POD" ]; then
       tcp_check "$APPSET_POD" argocd-redis-ha-haproxy 6379 deny "applicationset-controller to redis-ha-haproxy:6379"
     fi
   else
     REDIS_POD="$(kubectl -n "$ARGOCD_NS" get pod -l app.kubernetes.io/name=argocd-redis -o jsonpath='{.items[0].metadata.name}')"
   
     tcp_check "$SERVER_POD" argocd-redis 6379 allow "argocd-server to redis:6379"
     tcp_check "$REDIS_POD" argocd-repo-server 8081 deny "redis to repo-server:8081"
   
     if [ -n "$APPSET_POD" ]; then
       tcp_check "$APPSET_POD" argocd-redis 6379 deny "applicationset-controller to redis:6379"
     fi
   fi
   
   if [ -z "$FAILED_CHECKS" ]; then
     echo "MITIGATION CHECK: PASS"
   else
     echo "MITIGATION CHECK: FAIL"
     echo "$FAILED_CHECKS"
     exit 1
   fi
   

   Expected result: MITIGATION CHECK: PASS

Rollback

If required, take the following steps to remove the mitigation:

1. Delete the manual mitigation policies:

   kubectl -n "$ARGOCD_NS" delete networkpolicy \
     argocd-repo-server-manual-mitigation \
     argocd-redis-manual-mitigation \
     argocd-redis-ha-server-manual-mitigation \
     argocd-redis-ha-haproxy-manual-mitigation \
     --ignore-not-found
   

2. Confirm the rollback completed successfully:

   kubectl -n "$ARGOCD_NS" get networkpolicy
   kubectl -n "$ARGOCD_NS" get pods
   kubectl get applications.argoproj.io -A
   

   Confirm the following:

   • The manual mitigation policies are removed.
   • ArgoCD pods remain Running or Completed.
   • ArgoCD Applications remain Synced and Healthy.