tekton-pipeline-security

name

tekton-pipeline-security

description

Harden Tekton Pipelines on owned or authorized clusters: Task/Pipeline definitions, PipelineRun isolation, ServiceAccount RBAC, workspace and secret mounts, step image trust, Triggers EventListeners, and Chains provenance. Use when reviewing Tekton YAML, PipelineRun podTemplates, privileged steps, untrusted git resolvers, TriggerBindings, or CI that runs untrusted pull requests on Kubernetes — not third-party cluster abuse.

Tekton Pipeline Security

Assess and harden Tekton so pipeline workloads run with least privilege, trusted inputs and images, controlled secret access, and isolated runs. Prefer static review of Tasks, Pipelines, Triggers, and RBAC before live changes. Org-owned, lab, or explicitly authorized clusters only.

Scope And Authorization

• In scope: Tekton CRs (Task, ClusterTask, Pipeline, PipelineRun, TaskRun, Trigger*, EventListener), run ServiceAccounts and Roles, workspaces, resolvers, podTemplates, Chains/signing policy, and related CI manifests you own or are contracted to review.
• Out of scope: foreign-cluster abuse; using leaked pipeline tokens outside ROE; unapproved prod runs that mutate shared systems; host breakout proofs on shared production nodes.
• Prefer kubectl get/describe and non-prod first. Gate live Triggers, privileged podTemplates, and secret-mount experiments. Redact tokens, kubeconfigs, git/registry credentials, and PII from logs, results, and reports.

When To Use

• Authoring or reviewing Tekton Task / Pipeline / PipelineRun / TaskRun
• Step image, script, command, env, or mounts that may leak or escalate
• Pipeline ServiceAccounts, RoleBindings, default SA token automount
• Workspaces (PVC, secret, configMap) and param/result trust boundaries
• Triggers: EventListener, TriggerBinding/Template, interceptors, untrusted PR webhooks
• Resolvers (git, bundle, hub) and unsigned / floating task references
• Tekton Chains / SLSA provenance, signed runs, trusted resources
• Keywords: Tekton security, PipelineRun SA, privileged step, EventListener, workspace secret, Chains attestation, untrusted PR pipeline

Do not use as primary for:

Need	Skill instead
Generic GitHub Actions / GitLab CI patterns	ci-cd-pipeline-patterns
Live cluster RBAC / secret dump (lab)	kubernetes-pentesting
Org secret rotation, VCS leak IR	secrets-management-hygiene
Image non-root / layer secrets	dockerfile-best-practices
Lab container→host breakout	container-escape-techniques
Helm packaging of Tekton install	helm-chart-security
Task scripts and CR quality	code-quality-standards

Workflow

1. Inventory trust boundaries

1. Record cluster/namespace, Tekton version, who can create PipelineRuns, and whether Triggers accept external webhooks.
2. List Tasks/Pipelines (namespaced vs cluster), ClusterTasks, resolvers, run SAs.
3. Map trusted refs (main/tag) vs untrusted (fork PR, free-form git URL, unconstrained params).

# Owned/lab — metadata only
kubectl get task,pipeline,pipelinerun,taskrun,sa,eventlistener,trigger -n <ns>

2. ServiceAccount and RBAC least privilege

• Dedicated SA per pipeline class (build vs deploy); never default SA for runs.
• Limit Role verbs to what steps need (no casual * on secrets/pods/exec).
• Separate deploy SA/bindings from untrusted build/test runs.
• automountServiceAccountToken: false when steps do not call the API.
• Who may create PipelineRun/TaskRun is as important as step power.

3. Pod template, steps, and workspaces

Control	Hardened default
Security context	non-root; allowPrivilegeEscalation: false; drop ALL
Privileged / hostPath / hostNetwork	Off for app CI; document exceptions
Step images	Pin digest or immutable tag; org-approved only
Secrets	Minimal workspace/CSI mounts; never echo into results/logs
Workspaces	Isolate RW build space from secret mounts; no shared RW PVC across trust levels
Params/results	Untrusted input; no eval of params in scripts

Untrusted PR pipelines must not mount prod deploy credentials or cluster-admin SAs. Fix Task contracts against param injection; do not run offensive payloads against shared prod.

4. Triggers, resolvers, and supply chain

1. EventListener: authenticate webhooks (interceptors, shared secrets, CEL); restrict namespace and Trigger SA.
2. Bindings: allowlist branches/repos; do not pass arbitrary remote Task URLs from untrusted events into privileged runs.
3. Resolvers: pin bundle/git revisions; prefer signed/trusted resources; avoid floating public hub ClusterTasks in prod.
4. Chains: attest/sign release PipelineRuns; verify provenance per policy (pair container-image-signing for image sign/verify).
5. Dashboard/EL: authn/z; NetworkPolicy for listeners and SCM/registry egress.

5. Remediate and verify

Fix CRs and RBAC in GitOps; re-run non-prod PipelineRun; confirm SA cannot read unrelated secrets and untrusted Triggers cannot deploy. Apply code-quality-standards to Task scripts; live depth → kubernetes-pentesting.

Routing

Situation	Primary	Helper
Tekton Tasks/Pipelines/Runs, SA, workspaces, Triggers, Chains	This skill	—
Generic multi-platform CI stages/OIDC/cache	ci-cd-pipeline-patterns	this for Tekton-on-K8s
Live cluster RBAC/secrets assessment	kubernetes-pentesting	this for pipeline root cause
Secret lifecycle, leak IR, rotation	secrets-management-hygiene	this for mount/log paths
Step images / provenance signing	dockerfile-best-practices / container-image-signing	this for step refs / Chains
Privileged step breakout (lab)	container-escape-techniques	this for podTemplate evidence
Helm install of Tekton/EL; scripts/GitOps quality	helm-chart-security / code-quality-standards	this for runtime CR policy

Keep this skill primary for Tekton hardening; switch for generic SaaS CI, org secrets, or live cluster exploitation.

Output Checklist

• Authorization and cluster/namespace scope recorded (owned/lab/ROE only)
• Tasks, Pipelines, Runs, Triggers, resolvers, and run SAs inventoried
• Trusted vs untrusted paths separated (fork PR / free git URL)
• Dedicated least-privilege SA; default SA avoided; automount minimized
• PodTemplate: non-privileged, non-root, dropped caps, no host ns/path
• Step images pinned/approved; no floating public tasks in prod
• Secrets out of params/logs/results; prod creds off untrusted runs
• Workspaces isolate trust levels; shared PVC risk owned or fixed
• EventListener authenticated/filtered; Trigger SA cannot over-deploy
• Chains/signing where release policy requires; EL/Dashboard exposure intentional
• Evidence redacted; route to ci-cd-pipeline-patterns, kubernetes-pentesting, secrets-management-hygiene, image/signing skills, code-quality-standards as needed