opa-rbac-templates

name	opa-rbac-templates
description	OPA RBAC policies preventing cluster-admin privilege escalation, restricting privileged verbs, and blocking wildcard permissions.

OPA RBAC Templates

When to Use This Skill

RBAC policies control who can perform which actions on which resources. These templates prevent privilege escalation through overly permissive roles.

Wildcards Grant Unrestricted Access

RBAC rules with resources: ["*"] or verbs: ["*"] grant access to all current and future resources or actions. Avoid wildcards except for break-glass admin roles.

When to Apply

Scenario 1: Prevent Unauthorized Cluster-Admin

Block cluster-admin except for approved break-glass accounts:

# Enforced by: cluster-admin.yaml
# Result: Only subjects in approved list can receive cluster-admin binding
# Impact: Prevents privilege escalation to cluster-admin

Scenario 2: Block Dangerous RBAC Verbs

Prevent use of escalate, bind, impersonate:

# Enforced by: privileged-verbs.yaml
# Result: Roles cannot include escalate/bind/impersonate verbs
# Impact: Prevents users from granting themselves additional permissions

Scenario 3: Eliminate Wildcard Permissions

Require explicit resource and verb lists:

# Enforced by: wildcards.yaml
# Result: Roles must specify resources: ["pods"], not resources: ["*"]
# Impact: Reduces blast radius of compromised service accounts

Implementation

See the full implementation guide in the source documentation.

Techniques

RBAC Security Patterns

Least Privilege Principle

Grant minimum permissions required for each workload:

1. Start with no permissions - Service accounts have no default permissions
2. Add specific resources - pods, configmaps, not *
3. Add specific verbs - get, list, not *
4. Scope to namespace - Use Role instead of ClusterRole when possible

Defense Against Privilege Escalation

Block RBAC manipulation verbs:

• escalate - Allows creating roles with more permissions than creator has
• bind - Allows granting roles to arbitrary subjects
• impersonate - Allows acting as other users without authentication

Only cluster admins should have these verbs.

Time-Bounded Permissions

Use annotations to enforce temporary access:

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: temporary-debug-access
  annotations:
    rbac.expires: "2025-01-05T00:00:00Z"
subjects:
  - kind: User
    name: [e-mail]
roleRef:
  kind: ClusterRole
  name: debug-read-only

OPA policies can validate expiration and block expired bindings.

See reference.md for additional techniques and detailed examples.

Examples

See examples.md for code examples.

Full Reference

See reference.md for complete documentation.

Related Patterns

• OPA Templates Overview
• OPA Pod Security
• OPA Resource Governance

References

• Source Documentation
• AEL Enforce