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Apply the least privilege in the Authorization IAM. 31 | - ✅ Limiting access to etcd 32 | - Apply etcd Encryption 33 | - Use TLS communication 34 | - is ETCD access limited to control plane? 35 | - ✅ Apply host security benchmark: OpenSCAP, OVAL. Validate if your hosts are following the CIS benchmark. `Compliance` 36 | - ✅ Updates and patches 37 | - Update the kubernetes version with the fixed bugs 38 | - ✅ Certs: SSL/TLS for your Kubernetes Cluster 39 | - Automated issuance and renewal of certificates to secure Ingress with TLS 40 | - Secure pod-to pod communication with mTLS using private PKI Issuers 41 | - Supports certificate use cases for web facing and internal workloads 42 | 43 | > [cert-manager](https://cert-manager.io/) is a X.509 certificate controller for Kubernetes and OpenShift workloads. 44 | 45 | > Manage TLS Certificates in a Cluster - [Kubernetes official doc](https://kubernetes.io/docs/tasks/tls/managing-tls-in-a-cluster/) 46 | 47 | ## Kubernetes Security Features 48 | 49 | - ✅ Authorization: RBAC 50 | - ✅ Authentication: SSO 51 | - ✅ Secrets management 52 | - ✅ Pod Security policy 53 | - ✅ Network policy 54 | - ✅ Observability: Auditing API server 55 | 56 | ## Kubernetes Authorization - RBAC 57 | 58 | - ✅ Role-based Access Control - RBAC 59 | - *Follow the principle of least privilege* 60 | - Workload identity in Cloud providers: Employ workload identity to tie RBAC to the cloud provider’s authentication mechanism. 61 | - Avoid admin-level access in the cluster 62 | - [AquaSecurity/kubectl-who-can](https://github.com/aquasecurity/kubectl-who-can). Show who has RBAC permissions to perform actions on different resources in Kubernetes. 63 | - [FairwindsOps/rbac-manager](https://github.com/FairwindsOps/rbac-manager). This is an operator that supports declarative configuration for RBAC with new custom resources. 64 | 65 | - [Kubernetes RBAC: Asking for Forgiveness or Getting Permission](https://blog.aquasec.com/kubernetes-rbac) 66 | - [Privilege Escalation from Node/Proxy Rights in Kubernetes RBAC](https://blog.aquasec.com/privilege-escalation-kubernetes-rbac) 67 | - [Kubernetes RBAC: How to Avoid Privilege Escalation via Certificate Signing](https://blog.aquasec.com/kubernetes-rbac-privilige-escalation) 68 | 69 | ## Kubernetes Pod Security 70 | - ✅ [Pod security standards](https://kubernetes.io/docs/concepts/security/pod-security-standards/): Restricted, Baseline and Privileged. 71 | - ✅ Configure a [Security context](https://kubernetes.io/docs/tasks/configure-pod-container/security-context/) for a pod or container. 72 | - ✅ Container runtime with stronger isolation 73 | 74 | ## Kubernetes Secrets 75 | 76 | - ✅ Encrypt all your secrets 77 | - Mozilla's SOPS 78 | - Key Management stores in the Cloud Providers 79 | 80 | ## Kubernetes Network Security 81 | 82 | when’s the last time anyone discovered a sophisticated attack from a 83 | packet capture (PCAP) in Kubernetes? 84 | 85 | ![network-k8s](./img/network-k8s.png) 86 | >> [Image by Security Observability with eBPF](https://isovalent.com/data/isovalent_security_observability.pdf) 87 | 88 | - ✅ Network Policy 89 | - Use nano segmentation 90 | - Use network policy: manage cluster ingress and egress 91 | 92 | ## Kubernetes Supply Chain Security 93 | - ✅ Enforce image trust with Image signing 94 | - Image signing: Container Signing, Verification and Storage in an OCI registry. 95 | - [Cosign vs Notary by Rewanth](cosign-with-kubernetes-ensure-integrity-of-images-before-deployment) 96 | - ✅ Enabled Kubernetes [Admission controllers](https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/) to verify the image integrity. 97 | - ✅ SCA, SBOM 98 | 99 | ![container-signing](./img/container-signing.png) 100 | 101 | ## Kubernetes Thread Matrix 102 | 103 | - [Microsoft Threat Matrix](https://microsoft.github.io/Threat-Matrix-for-Kubernetes/) 104 | 105 | ## Common Attacks 106 | 107 | - Abuse credentials: RBAC, service accounts system:masters 108 | - Poisoned Images / Malicious Images in the registry 109 | - Supply chain mitigation: Secure Ci/CD env, Image assurance, Image signing 110 | - Privileged Escalation – Breaking out of the Container: Excessive capabiiities such as CAP_SYS_ADMIN, CAP_NET_ADMIN, CAP_SYS_PTRACE 111 | - Escape to Host- Kubernetes Privilege Pod application 112 | - writable hostPath mount: Avoid with misconfigurations k8s tools 113 | - [CVE-2022-0185: Kubernetes Container Escape Using Linux Kernel Exploit](https://www.crowdstrike.com/blog/cve-2022-0185-kubernetes-container-escape-using-linux-kernel-exploit/) 114 | 115 | - Backdoor container - Persistence: capture the contents of the service account token mounted in the container 116 | - [Doki Malware](https://attack.mitre.org/software/S0600/) 117 | - Used secret management for your application data. 118 | - Cryptominers 119 | - [Kinsing Malware](https://attack.mitre.org/software/S0599/) 120 | - Laterally moving within the cluster, Network scanning: Avoid with network policy or network segmentation. 121 | - Misconfigured Kubelet API: Avoid with Kubernetes hardening tools. 122 | - Set to false the `--anonymous-auth` flag in the kubelet component. 123 | - [Hildegard Malware](https://attack.mitre.org/software/S0601/) 124 | - Application exploit (RCE, SSRF, XXE, etc.) 125 | - Reverse Shell: Remote code execution (RCE) that opens a reverse shell connection to a suspicious domain that the attacker is listening. 126 | >> The workload wasn’t restricted by the container runtime and has overly permissive Linux capabilities that 127 | enables the attacker to mount in the /etc/kubernetes/manifests directory from the host into the container. 128 | >> The attacker then drops a privileged pod manifest in kubelet’s manifest directory. The attacker now has a high-availability, kubelet-managed backdoor into the cluster that supersedes any IAM (identity and access management) or RBAC policies. 129 | - Fileless attacks in containers 130 | - [Using memfd_create syscall](https://youtu.be/dizRKAjuhS0) 131 | - SSRF attacks to the Kubernetes API server 132 | 133 | - Denial of Service (DoS) or a Distributed Denial of Service (DDoS): Avoid with misconfigurations k8s tools 134 | - ✅ Limit the resources (CPU, memory) in the pods 135 | - [Goldilocks](https://github.com/FairwindsOps/goldilocks) - identify a starting point for resource requests and limits. 136 | - ✅ Limit the resources (CPU, memory) using Quotes by namespace/cluster. 137 | - ✅ Set limits about traffic in the ingress policy. You can set limits on the number of concurrent connections, the number of requests per second, minute, or hour; the size of request bodies. 138 | - Fork bomb: Avoid with misconfigurations k8s toolss 139 | 140 | ## Policy as a code 141 | OPA allows users to set policies across infrastructure and applications. 142 | 143 | - Standard policies. 144 | - Organization-specific policies 145 | - Environment-specific policies 146 | 147 | Some controls examples: 148 | • Which registries images can be downloaded from 149 | • Which OS capabilities a container can execute with 150 | • Which namespaces are allowed to run sensitive workloads 151 | • Labels that must be specified for certain resources 152 | • Disallowing deprecated or dangerous resource types 153 | • Enforcing naming schemes or internal standards 154 | 155 | ### Integrates shift-left Kubernetes Security 156 | Run security validation checks in your CI/CD pipeline. Check the manifest written in in Yaml, Terraform, etc 157 | 158 | - [x] IaC and automation reduce human error by creating predictable results 159 | 160 | ## Kubernetes Reliability Best Practices 161 | - Simplicity vs Complexity 162 | - Service delivery vs traffic routing. Manually maintained DNS entries, Service delivery is required because your application is scaling in and out, and changes are happening at a fast rate. 163 | - Configuration management tools: Puppet, Ansible, Terraform 164 | - Application configuration: ConfigMaps or Secrets 165 | - High-availability (HA) architecture / fault tolerance 166 | - Resource limits and auto-scaling. *set limits on what a pod can consume to increase reliability. This avoids the noisy neighbor problem* 167 | - Liveness and readiness probes. *configure liveness probes and readiness probes to provide your cluster with the ability to self-heal* 168 | 169 | ### Key Monitoring Alerts 170 | - Kubernetes deployment with no replicas 171 | - Horizontal Pod Autoscaler (HPA) scaling issues 172 | - Host disk usage 173 | - High IO wait times 174 | - Increased network errors 175 | - Increase in pods crashed 176 | - Unhealthy Kubelets 177 | - nginx config reload failures 178 | - Nodes that are not ready 179 | - Large number of pods that are not in a Running state 180 | - External-DNS errors registering records 181 | 182 | ## Kubernetes Security Tools 183 | - [Penetration tool - Peirates](https://github.com/inguardians/peirates) 184 | - [Kube-hunter](https://github.com/aquasecurity/kube-hunter) 185 | - [FairwindsOps/Polaris](https://github.com/FairwindsOps/Polaris). Validation of best practices in your Kubernetes clusters. 186 | - [Kubescape](https://github.com/kubescape/kubescape) 187 | - [AquaSecurity/appshield](https://github.com/aquasecurity/appshield). Security configuration checks for popular cloud native applications and infrastructure. 188 | - [Trivy-operator] 189 | 190 | ## Kubernetes Security Guides 191 | - [Kubernetes Hardening Guide by NSA/CISA](https://media.defense.gov/2022/Aug/29/2003066362/-1/-1/0/CTR_KUBERNETES_HARDENING_GUIDANCE_1.2_20220829.PDF) 192 | - [Containers Matrix by Mitre](https://attack.mitre.org/matrices/enterprise/containers/) 193 | 194 | ## Kubernetes CI/CD Artifacts 195 | - argoCD 196 | - gitops 197 | - terraform 198 | - helm 199 | - Istio help handling mutual TLS encryption inside the cluster. 200 | 201 | ## Further reading: 202 | - [Fairwinds - Kubernetes Best Practices](https://f.hubspotusercontent40.net/hubfs/2184645/Kubernetes-Best-Practices-WhitePaper.pdf) 203 | - [Kubernetes Security Cheat Sheet by Owasp](https://cheatsheetseries.owasp.org/cheatsheets/Kubernetes_Security_Cheat_Sheet.html) 204 | - [gaps in your public cloud kubernetes security posture](https://itnext.io/how-to-spot-gaps-in-your-public-cloud-kubernetes-security-posture-b9cd375f1b25) 205 | ## Collaborate 206 | 207 | If you find any typos, errors, outdated resources; or if you have a different point of view. Please open a pull request or contact me. 208 | 209 | Pull requests and stars are always welcome 🙌 210 | -------------------------------------------------------------------------------- /_config.yml: -------------------------------------------------------------------------------- 1 | theme: jekyll-theme-minimal -------------------------------------------------------------------------------- /img/4c-cloud-native.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/krol3/kubernetes-security-checklist/6557c718de80251be19397f7e587b51e4e7af7a0/img/4c-cloud-native.png -------------------------------------------------------------------------------- /img/container-signing.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/krol3/kubernetes-security-checklist/6557c718de80251be19397f7e587b51e4e7af7a0/img/container-signing.png -------------------------------------------------------------------------------- /img/infra-k8s-security.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/krol3/kubernetes-security-checklist/6557c718de80251be19397f7e587b51e4e7af7a0/img/infra-k8s-security.png -------------------------------------------------------------------------------- /img/network-k8s.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/krol3/kubernetes-security-checklist/6557c718de80251be19397f7e587b51e4e7af7a0/img/network-k8s.png --------------------------------------------------------------------------------