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Runbook · Contain
RB-CONTAIN-016

Web Application Access Restriction

1. Prerequisites

  • Application, API, route, endpoint, feature, tenant, or function requiring restriction identified
  • Access to relevant application, WAF, CDN, API gateway, identity, or configuration controls
  • Business-critical access requirements known
  • Rollback method available
  • Incident ticket or change record created

2. Step-by-Step Instructions

  1. Define Restriction Scope

    • Identify the application, API, route, endpoint, tenant, feature, admin function, upload path, export path, or integration to restrict.
    • Record the reason for restriction and required time window.
  2. Identify Required Access

    • Determine which users, services, source networks, methods, regions, tenants, or integrations must remain allowed.
    • Identify access that can be blocked, limited, or challenged.
  3. Select Restriction Method

    • Choose the least disruptive effective control:
      • Disable route, feature, upload, export, or integration
      • Apply WAF, CDN, or API gateway rule
      • Require authentication or step-up authentication
      • Apply IP, ASN, geo, tenant, user, or service allowlist/denylist
      • Restrict HTTP methods, request size, file types, or high-risk parameters
      • Apply rate limits, bot controls, or request throttling
      • Remove admin interface from public exposure
  4. Record Current State

    • Capture current routing, WAF/CDN/API gateway rules, feature flags, access policies, rate limits, and relevant application configuration.
    • Record rollback values before making changes.
  5. Apply Restriction

    • Implement the selected restriction.
    • Keep the scope as narrow as possible.
    • Record exact rule, configuration, feature flag, route, or policy changed.
  6. Validate Restriction

    • Confirm blocked or restricted access is no longer allowed.
    • Confirm required users, services, tenants, and business-critical flows still work.
    • Check for unintended outage or authentication failures.
  7. Monitor for Bypass

    • Review logs for alternate routes, changed payloads, new source IPs, token reuse, method switching, rate-limit evasion, or tenant/object switching.
    • Adjust restriction if bypass attempts continue.
  8. Record Restriction Details

    • Document restriction scope, method, timestamp, configuration change, validation result, expected duration, rollback condition, and known business impact.
  9. Review Continued Need

    • Reassess whether the restriction is still required.
    • Remove, narrow, or replace temporary controls once durable remediation is complete.
  10. Restore Access

    • Remove or reduce the restriction when criteria are met.
    • Validate normal functionality.
    • Record restoration time and final state.

3. Post-Action

  • Confirm restriction remains effective and scoped appropriately.
  • Record business impact, bypass attempts, and required follow-up changes.
  • Preserve before/after configuration where applicable.

Contributor

Jayden Vo GitHub: https://github.com/jayden-vo

Contributed to the Arcana Incident Response Documentation Framework.