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OWASP Cheat Sheet Series · 1 min read

Authorization Cheat Sheet

Practical design guidance covering least privilege, deny-by-default behavior, consistent per-request decisions, failure handling, logging, and authorization regression tests.

Open the reference Implementation GuideReviewed 2026-10-02

How to use this reference

Document which identities may perform which operations on each resource and check implementation and tests against that policy.

Before reading

  • Authentication versus authorization
  • Application roles and resource ownership
  • Basic server-side development

Context and limits

    Related visual models

    An incoming browser message first passes origin, sender-context and format validation. A separate decision checks the operation and recipient. Failed checks reject the message without disclosure or state change. Approved content remains data and only the permitted action is performed.

    Conceptual model Diagram

    Browser messages need separate trust checks

    Original defensive model combining OWASP messaging and authorization guidance with the linked historical cases. These are independent design checks, not a vendor patch diagram or an operational reproduction.

    Reviewed 2026-10-02Read
    A caller requests a combined view using required source A and required source B. Each source has its own authorization decision for that caller. Either No denies the combined view without protected source data. Both Yes decisions are required at an explicit AND gate before composition. Field selection preserves each source’s field permissions, and only permitted data is returned.

    Conceptual model Diagram

    Combined views preserve every source's access boundary

    Original conceptual model for a view that requires multiple independently protected sources. Permission to use one source cannot authorize another source. The convergence is an AND requirement: both source decisions…

    Reviewed 2026-10-04Read
    A failure retains the original caller, action and resource. An explicit access denial stops without protected data. A known recoverable operational failure can propose a fallback, but switching execution identity grants no extra caller entitlement. A separate application-policy decision evaluates that fallback for the original caller. Denied or indeterminate decisions stop without protected data. A permitted, scoped fallback returns only caller-permitted data.

    Conceptual model Diagram

    Fallbacks must preserve the original caller's authority

    Original editorial defensive synthesis of the Instagram embedding disclosure and OWASP authorization guidance. The researcher attributes the disclosure to error handling that retrieved protected content under an…

    Reviewed 2026-10-04Read

    Sources and provenance

    1. Authorization Cheat Sheet OWASP Cheat Sheet Series · reviewed 2026-10-02

    Record reviewed 2026-10-02. Snapshot 53796974ace8. Open the complete JSON contract.

    GitHub snapshot 2026-10-04

    53796974ace8 · JSON exports & schemas · CC BY 4.0 content / MIT software