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Authorization / Broken Access Control Resources

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A curated AppSec resource library covering XSS, SQLi, SSRF, IDOR, RCE, XXE, OSINT, and more.

Authorization / Broken Access Control

Authorization vulnerabilities occur when applications fail to properly enforce access controls, allowing users to perform actions or access resources beyond their intended permissions. Broken Access Control consistently ranks as the #1 risk in the OWASP Top 10, encompassing issues like privilege escalation (both vertical and horizontal), missing function-level access controls, and insecure direct object references at the authorization layer. Unlike authentication (verifying who you are), authorization determines what you are allowed to do — and flaws here can expose entire administrative interfaces, allow users to modify other accounts, or grant elevated privileges through parameter tampering, forced browsing, or JWT manipulation. Modern applications with complex role hierarchies, microservice architectures, and API-first designs face particular challenges in maintaining consistent authorization checks across every endpoint and resource.

Date Added Link Excerpt
2026-05-11 NEW 2026Devastating 'Dirty Frag' exploit leaks out gives immediate root access on most Linux machines since 2017 no patches available no warning given Copy Fail-like vulnerability had its embargo broken newsTool that provides immediate root access on most Linux machines since 2017 due to the Dirty Frag vulnerability. This local privilege escalation exploit leverages a zero-copy operation in IPSec-related modules, specifically affecting "xfrm-ESP Page Cache Write" and "RxRPC Page-Cache Write." Distributions like Ubuntu, Arch, RHEL, and Fedora are impacted. Mitigation involves disabling esp4, esp6, and rxrpc kernel modules. The exploit code is available via a GitHub repository for testing.
2026-05-06 NEW 2026Zero-Auth Flaw Exposes DoD Contractor to Cross-Tenant Data Access news API SecA critical zero-authentication flaw in a contractor's system has exposed the Department of Defense (DoD) to cross-tenant data access risks. This vulnerability allowed unauthorized access to sensitive information without any credentials. The specific details and the contractor involved were not disclosed. This breach highlights significant security concerns for government contractors and the sensitive data they handle. → cybersecuritynews.com
2026-05-04 2026Critical MOVEit Automation auth bypass vulnerability fixed (CVE-2026-4670) newsWriteup of CVE-2026-4670, a critical authentication bypass in Progress Software's MOVEit Automation, enabling unauthorized administrative control and data exposure. This vulnerability, along with a privilege escalation flaw (CVE-2026-5174), affects specific older versions and can be exploited via low-complexity attacks by unauthenticated or authenticated attackers, respectively. Upgrading to patched versions 2025.1.5, 2025.0.9, or 2024.1.8 is strongly advised to remediate these issues. → helpnetsecurity.com
2026-05-02 2026CVE-2026-31431: Copy Fail vulnerability enables Linux root privilege escalation across cloud environments newsAnalysis of CVE-2026-31431, nicknamed "Copy Fail," details a high-severity Linux kernel vulnerability affecting Red Hat, Ubuntu, SUSE, and AWS Linux. This logic flaw in the AF_ALG module allows local unprivileged users to gain root privileges by corrupting the kernel page cache, impacting cloud workloads and Kubernetes clusters. The exploit, a small script leveraging the splice() system call and AF_ALG, enables container breakout and lateral movement, posing a significant risk to multi-tenant environments. Microsoft Defender provides detection insights, mitigation recommendations, and hunting guidance. → microsoft.com
2026-04-30 2026Escape AI Pentesting Agents 2.0 newsLibrary for agentic pentesting, offering a multi-agent architecture with a coordinator agent orchestrating specialized agents for tasks like reconnaissance, XSS detection (including reflected, stored, DOM-based, CSP bypasses, and framework-specific attacks), and application crawling. This system chains multiple techniques, adapts strategies in real-time, and produces evidence-rich findings with executable proof and reasoning traces, designed to improve upon traditional DAST scanner limitations and provide programmable security gates for CI/CD pipelines. → securityboulevard.com
2026-04-22 2026Rights Management Approaches: ACL, RBAC, ABAC, ReBAC beginnerGuide on access control models, including ACL, RBAC, ABAC, and ReBAC, for defining architectural security requirements. It covers practical guidance, trade-offs like UX friction and latency, and discusses Google's Zanzibar system as a canonical source for ReBAC. The guide offers phased roadmaps for implementation, focusing on inventory, RBAC baselines, context rules, and continuous verification, while highlighting common antipatterns and metrics for operational control.
2026-04-22 2026OPA, Cedar, OpenFGA: Why Are Policy Languages Trending Right Now? newsLibrary for understanding policy languages like OPA (Rego), Cedar, and OpenFGA, which are trending for Identity and Access Management (IAM) due to increasing authorization complexity. These declarative languages offer readable, performant, and auditable ways to manage fine-grained access controls across microservices, databases, and evolving user requirements, including AI agents. The article discusses authorization challenges, layered architectural principles for decision-making, and the benefits of policy-as-code.
2026-04-22 2026OPA vs OpenFGA: A Technical Comparison of Policy Engines intermediateReference comparing Open Policy Agent (OPA) and OpenFGA, two distinct policy engines. OPA, a CNCF project, uses Rego for centralized, rule-based access control, excelling in complex attribute-based decisions and infrastructure authorization like Kubernetes admission control. OpenFGA, based on Google's Zanzibar model, employs a tuple-based relationship approach for fine-grained, object-level permissions and hierarchical access, suitable for collaborative features and social network-style sharing. The comparison details their core concepts, architectural differences, and use case scenarios.
2026-04-22 2026Implementing Google Zanzibar: A Demonstration of Its Basics intermediateLibrary demonstrating Google Zanzibar fundamentals, focusing on its Relationship-Based Access Control (ReBAC) model. The entry explores Zanzibar's data model, relationship tuples with examples like `file123#owner@alice`, and provides a PostgreSQL implementation for storing these tuples, illustrating concepts such as ownership and membership.
2026-04-22 2026How to Protect Your API with OpenFGA: ReBAC Concepts to Practical Usage intermediateLibrary introducing Relation-Based Access Control (ReBAC) via OpenFGA, an open-source implementation of Google's Zanzibar concepts. It details ReBAC principles, contextual conditions, and attribute-based access, offering practical examples for protecting APIs and managing complex authorization logic. The library covers ReBAC concepts, OpenFGA's features like time-based and status-driven permissions, and contrasts its approach with traditional methods such as RBAC and ABAC, highlighting benefits in maintainability and scalability.
2026-04-22 2026How Google Drive Models Authorization: A Look into Zanzibar intermediateLibrary implementing Google's Zanzibar authorization system, which utilizes relationship-based access control (ReBAC) to manage permissions for services like Google Drive. Zanzibar centers on user-resource relationships rather than roles, enabling complex, nested access models with high availability and low latency through its globally distributed database and consistency protocol, which employs timestamps and "zookies" to ensure accurate permission checks in distributed environments.
2026-04-22 2026Common Bug Bounty Vulnerabilities: A Technical Deep Dive for Hunters in 2026 intermediateReference outlining common bug bounty vulnerabilities, detailing techniques and tools such as local LLM integration with Ollama for response analysis, Burp Suite extensions like Authz and Turbo Intruder for IDOR testing, Interactsh for SSRF callbacks, sqlmap for SQL injection, InQL for GraphQL fuzzing, and Burp's DOM Invader for XSS, alongside methods for exploiting business logic flaws.
2026-04-22 2026CVE-2026-32877 - Red Hat Security Advisory newsCVE-2026-32877 - Red Hat Security Advisory
2026-04-22 2026CVE 2026: When Identity Breaks and Legacy Code Bites Back newsAnalysis of CVE-2026-24858, a critical Fortinet SSO logic flaw, and CVE-2026-24061, an argument injection in GNU InetUtils' telnetd, highlighting early 2026's vulnerability landscape dominated by legacy code exploits and advanced Agentic AI threats. The analysis details the mechanics and exploit logic for both, emphasizing the reduced exploitation windows and the need for continuous, AI-driven validation to combat automated exploitation. → penligent.ai
2026-04-22 2026What is Google Zanzibar? beginnerLibrary detailing Google Zanzibar, a consistent, global authorization system that implements relationship-based access control (ReBAC). It explains namespaces, relation tuples with the format `<object>#<relation>@<user>`, schema configuration, and the 'zookie' for user-specified consistency. The system leverages Google's Spanner database and employs layered caches and request hedging for scalability and performance, offering core API methods for read, write, watch, check, and expand operations.
2026-04-19 2026Broken Access Control: The Quiet Killer in Web Applications beginnerBroken Access Control: The Quiet Killer in Web Applications → infosecwriteups.com
2026-04-19 2026Broken Access Control: The Silent Web Vulnerability beginnerBroken Access Control: The Silent Web Vulnerability
2026-04-19 2026Broken Access Control: The 40% Surge in 2025 newsLibrary for identifying and preventing broken access control vulnerabilities, a pervasive and critical application security risk that surged in 2025. This library addresses common weaknesses like vertical and horizontal privilege escalation, Insecure Direct Object References (IDOR), forced browsing, and missing function-level access control, which attackers exploit to gain unauthorized data access. It is designed to mitigate the impact of these flaws, which are exacerbated by rapid development cycles, complex architectures, and the introduction of vulnerabilities from AI-generated code.
2026-04-19 2026OWASP Top 10 2025 — A01 Broken Access Control beginnerReference detailing OWASP Top 10 2025 A01: Broken Access Control, the most prevalent vulnerability. It highlights common weaknesses like insecure direct object references, privilege escalation, JWT manipulation, CORS misconfigurations, and force browsing. Prevention strategies emphasize server-side enforcement, deny-by-default principles, robust access control mechanisms, and proper session management with short-lived JWTs or refresh tokens. The document also mentions related CWEs such as CWE-200, CWE-201, CWE-918 (SSRF), and CWE-352 (CSRF), and provides example attack scenarios. → owasp.org
2026-04-16 2026Enhancing OAuth 2.0 Security with PKCE: Deep Dive advancedWalkthrough of OAuth 2.0 integration with PKCE, detailing how Omnissa Intelligence uses the Proof Key for Code Exchange extension to prevent authorization code interception attacks when connecting with External Partner services. The process involves `code_verifier`, `code_challenge`, and `code_challenge_method=S256` to securely exchange authorization codes for access tokens, safeguarding against session hijacking and man-in-the-middle attacks.
2026-04-16 2026Attacks via OAuth Authorization Code Injection intermediate AuthNAttacks via OAuth Authorization Code Injection
2026-04-16 2026Security Benchmarking Authorization Policy Engines: Rego, Cedar, OpenFGA advancedFramework for dynamically evaluating authorization policy engines, including Rego, Cedar, OpenFGA, and Teleport ACD. This system automates security benchmarking and robustness testing by executing predefined test cases in isolated Docker containers for each engine, comparing actual results against expected outcomes to identify potential threats and vulnerabilities.
2026-04-16 2026Privilege Escalation by JWT Token Manipulation intermediatePrivilege Escalation by JWT Token Manipulation
2026-04-16 2026JWTs Under the Microscope: Exploiting Auth Weaknesses - Traceable intermediateLibrary for identifying and exploiting JWT authentication weaknesses. It details vulnerabilities like Improper JWT Signature Validation, JWT Algorithm Confusion, JWT Weak Secret, and attacks leveraging KID fields (SQL Injection, SSRF, Path Traversal), JKU/X5U misuse, X5T collisions, and payload manipulation leading to Broken Object Level Authorization (BOLA) and Broken Functional Level Authorization (BFLA), as well as JWT Expired Token issues.
2026-04-16 2026Privilege Escalation via IDOR and ACL Bypass in SaaS intermediatePrivilege Escalation via IDOR and ACL Bypass in SaaS
2026-04-16 2026Organization Takeover via Privilege Escalation (IDOR) intermediateOrganization Takeover via Privilege Escalation (IDOR)
2026-04-16 2026Horizontal Privilege Escalation via IDOR intermediateHorizontal Privilege Escalation via IDOR
2026-04-16 2026Fine-Grained Authorization: Technical Guide for Microservices intermediateGuide to fine-grained authorization for microservices, moving beyond traditional RBAC to Relationship-Based Access Control (ReBAC). It details the limitations of RBAC in dynamic environments and advocates for centralized policy engines like Open Policy Agent (OPA) and Zanzibar-inspired systems (e.g., OpenFGA). The guide provides a practical roadmap for implementation, focusing on auditing relationships, centralizing the source of truth, and iteratively decoupling authorization logic from individual services.
2026-04-16 2026RBAC vs ABAC vs ReBAC: How to Choose Access Control Models beginnerLibrary comparing Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC), and Relationship-Based Access Control (ReBAC). It details how RBAC, while simple, suffers from "Role Explosion" due to complexity in systems like AWS IAM and Kubernetes. ABAC is presented as a solution, using attributes and dynamic evaluation instead of static roles, exemplified by OPA and AWS IAM's Condition blocks. ReBAC principles are also touched upon, particularly in the context of Azure's resource hierarchy inheritance.
2026-04-15 2026Privilege Elevation Dominates Massive Microsoft Patch Update newsLibrary of patches addressing Microsoft's April 2026 update, which included 165 CVEs, with a significant portion being elevation-of-privilege bugs. Key vulnerabilities detailed include CVE-2026-32201 (a SharePoint Server spoofing zero-day actively exploited), CVE-2026-33825 (a Defender privilege escalation zero-day), CVE-2026-33824 (a critical RCE in Windows IKE Service Extensions), and CVE-2026-33827 (a rare unauthenticated RCE in Windows secure tunneling). The update also featured numerous fixes for Microsoft Edge and Chromium. → darkreading.com
2026-04-14 2026Critical etcd Auth Bypass Flaw Lets Attackers Access Sensitive Cluster APIs Without Authorization newsCritical etcd Auth Bypass Flaw Lets Attackers Access Sensitive Cluster APIs Without Authorization https://ift.tt/3a7iPej → cyberpress.org
2026-04-11 2026RBAC vs ABAC vs PBAC - Styra beginnerLibrary comparing Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC), and Policy-Based Access Control (PBAC). It details RBAC's traditional role-centric limitations, ABAC's attribute-driven flexibility, and PBAC's policy-as-code approach. The resource highlights how Styra DAS leverages PBAC and OPA for unified authorization, bridging policy formulation and implementation challenges.
2026-04-11 2026Policy as Code: Fine-Grained Authorization intermediateLibrary detailing Policy as Code for fine-grained authorization, featuring discussions on Rego for Open Policy Agent (OPA), AWS Cedar, and OpenFGA. The resource highlights the practice of defining policies with code for dynamic and adaptable management, distinguishing between validation and authorization, and emphasizing how policy languages abstract API complexities for easier rule definition and enforcement. Experts Jimmy Ray and Omer Zuarets share insights on applying policy as code in cloud-native security and simplifying policy implementation through tooling.
2026-04-11 2026Policy Engine Showdown: OPA vs OpenFGA vs Cedar intermediateReference to a panel discussion comparing application policy engines OPA, OpenFGA, and Cedar. The session, "Policy Engines Showdown," featured engineers discussing the strengths, trade-offs, and practical considerations of each engine, including OpenFGA's ReBAC model, Cedar's policy-driven approach, and OPA's multipurpose flexibility. The goal was to help developers select the best decision engine for their specific use cases, highlighting that suitability depends on implementation needs rather than a single "winner." The discussion also touched upon tools like OPAL for policy synchronization.
2026-04-11 2026ReBAC Authorization Academy - Oso beginnerLibrary exploring Relationship-Based Access Control (ReBAC) for application security, using the GitClub example to illustrate how permissions can be organized based on relationships between resources like users, repositories, and issues. It contrasts ReBAC with Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC), highlighting how ReBAC can elegantly handle data ownership scenarios where users need specific permissions on resources they created or are directly associated with. The library guides developers to leverage existing data structures to define these relationships, providing a natural and intuitive authorization model that complements traditional RBAC.
2026-04-11 2026RBAC vs ABAC vs PBAC - Oso beginnerLibrary for implementing consistent, maintainable authorization across distributed systems. It details Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC), and Policy-Based Access Control (PBAC), showcasing how Oso's Polar language enables declarative definition and enforcement of RBAC and ABAC through PBAC. This approach centralizes authorization logic into a single policy engine, ensuring uniform decisions based on user roles, attributes, and contextual data, enhancing auditability and simplifying evolution of access control policies across microservices.
2026-04-11 2026RBAC vs ABAC vs ReBAC - Oso beginnerReference detailing RBAC, ABAC, and ReBAC access control paradigms, comparing their strengths and limitations for applications. It highlights RBAC's role-based assignments, ABAC's attribute-driven policies, and ReBAC's relationship-based permissions. The document explains how these models can be combined for fine-grained authorization and suggests Oso as a tool to simplify implementation.
2026-04-11 2026Fine Grained Authorization using SpiceDB for RAG intermediateLibrary implementing fine-grained authorization for RAG using SpiceDB. This resource details how to integrate SpiceDB with Pinecone, Langchain, and OpenAI to enforce relationship-based access control (ReBAC) on document retrieval for AI applications. It covers schema definition, relationship writes, and querying authorized resources to pre-filter vector database searches, enhancing both security and efficiency in enterprise AI.
2026-04-11 2026Relationship-Based Permissions in SpiceDB intermediateLibrary for managing application permissions using Relationship-Based Access Control (ReBAC). SpiceDB, inspired by Google's Zanzibar, stores relationships between subjects and resources to efficiently answer permission queries. It supports robust write patterns, including two-phase commits with relational databases and streaming commits via systems like Kafka, ensuring data consistency. Alternatively, relationships can be stored solely within SpiceDB, simplifying application logic and enabling schema-driven permission computation. Asynchronous updates are also an option for applications tolerating less strict consistency.
2026-04-11 2026Introduction to Google Zanzibar beginnerReference on Google Zanzibar, an authorization system developed to manage permissions across Google's vast product suite, detailing its relationship-based access control (ReBAC) model. It explains how Zanzibar overcomes the limitations of application-specific authorization, addresses the "new enemy problem" through external consistency guarantees, and scales to handle billions of users and trillions of objects with low latency. The resource also highlights how open-source tools like SpiceDB can be used to implement similar systems, drawing parallels to Google's internal infrastructure and the significance of the 2019 Zanzibar research paper.
2026-04-11 2026OpenFGA: Open-Source Engine for Access Control beginnerLibrary for relationship-based access control, OpenFGA is an open-source, high-performance engine inspired by Google’s Zanzibar system. It allows developers to define and enforce fine-grained permissions with support for multiple storage backends, including PostgreSQL and MySQL, and offers APIs and SDKs in Java, Node.js, Go, Python, and .NET. OpenFGA integrates relationship-based, role-based, and attribute-based access control models, and includes a CLI, playground, and Terraform provider for easier management and testing. Notable adopters include Auth0 and Grafana Labs. → helpnetsecurity.com
2026-04-11 2026Announcing OpenFGA newsLibrary for fine-grained authorization, OpenFGA, is an open-source engine inspired by Google's Zanzibar. It allows developers to model complex access control rules, integrate them consistently across applications, and manage permissions efficiently at scale. OpenFGA features an expressive modeling language, HTTP APIs for checking and writing permissions, and supports various integrations with identity providers and proxies, addressing security, compliance, and privacy needs for modern collaborative and social applications, effectively tackling OWASP's top risk: broken access control.
2026-04-11 2026Authorization Concepts - OpenFGA beginnerReference detailing OpenFGA's approach to authorization, explaining Fine-Grained Authorization (FGA) and contrasting Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC), Policy-Based Access Control (PBAC), and Relationship-Based Access Control (ReBAC). It highlights ReBAC as a superset of RBAC and a solution for ABAC scenarios, noting OpenFGA extends ReBAC with Conditions and Contextual Tuples, drawing parallels to Google's Zanzibar system.
2026-04-11 2026Cedar Policy Language Complete Guide intermediateLibrary for fine-grained authorization, Cedar is an open-source policy language built in Rust that decouples access control from application logic. It supports RBAC, ABAC, ReBAC, and *BAC models, and is designed for simplicity, expressiveness, and performance, allowing for modular and reusable authorization policies. Cedar's evaluation logic prioritizes `forbid` statements, ensuring requests are denied if any matching `forbid` policy exists.
2026-04-11 2026Amazon Verified Permissions - Cedar intermediateLibrary for externalizing authorization and centralizing policy management, Amazon Verified Permissions leverages the Cedar policy language to enable developers to build secure applications and align with Zero Trust principles. It accelerates development by decoupling authorization from business logic, streamlining security with intuitive, policy-based access controls that support common frameworks. This service helps protect resources, manage user access according to the principle of least privilege, and facilitates granular authorization decisions. Users include TELUS for smart home device permissions, Grosvenor Engineering Group for building asset access, and STEDI for protecting healthcare transaction endpoints. → aws.amazon.com
2026-04-11 2026Cedar Policy Language Reference intermediateReference for Version 4.5 of the Cedar policy language, used for writing authorization policies and making decisions. Cedar decouples business logic from authorization, allowing applications to query an engine for "allow" or "deny" decisions based on policies, entities, context, and a schema. This separation simplifies updates and testing, as security teams can modify policies without touching application code. Cedar supports attributes, logical operators, and dynamic evaluation for fine-grained control, role-based access control (RBAC), and attribute-based access control (ABAC), with features like fast, scalable, and bounded-latency evaluation.
2026-04-11 2026Basic ABAC with OPA and Rego - AWS intermediateLibrary demonstrating basic Attribute-Based Access Control (ABAC) with OPA and Rego. It provides example Rego code snippets for a fictional Payroll microservice, illustrating how to enforce policies such as "Employees can read their own salary" and "Employees can read the salary of anyone who reports to them," utilizing external data for manager-report relationships.
2026-04-11 2026OPA Rego Language Tutorial beginnerTutorial on Rego, the declarative policy language for Open Policy Agent (OPA), detailing its fundamental constructs and mechanisms. Learn how Rego's logic-based syntax enables codifying rules for authorization, configuration validation, and data filtering, particularly within Kubernetes and Envoy. The tutorial covers writing Rego policies, including decisions, variable assignments, and using the "some" keyword for iterating over data structures, along with best practices for effective policy authoring.
2026-04-11 2026What is Open Policy Agent (OPA)? beginnerLibrary for managing cloud-native policies, Open Policy Agent (OPA) offers a unified, context-aware approach by decoupling policy enforcement from application code. It uses the Rego policy language for expressive, declarative rules, enabling security and compliance through policy-as-code, consistency across Kubernetes, microservices, and CI/CD pipelines, and efficient updates via a centralized policy library. → wiz.io
2026-04-11 2026OPA: Best Practices for Secure Deployment - CNCF intermediateLibrary for secure Open Policy Agent (OPA) deployment, focusing on preventing vulnerabilities like remote calls and Windows UNC path exploits by emphasizing separation of policy code from application code, decoupling schema and data through external sources, and structured data management. It highlights best practices derived from large-scale OPA usage, including techniques for restricting sensitive built-ins and leveraging tools like OPAL for synchronized policy and data updates.

Related Topics

IDOR 91 resources Access control flaws via predictable object references API Security 220 resources REST and API-specific vulnerability patterns CSRF 70 resources Forged authenticated requests from cross-origin pages Bug Bounty 299 resources Finding and reporting vulnerabilities for rewards
Compare: AuthN vs AuthZ · IDOR vs BOLA

Frequently Asked Questions

What is broken access control?
Broken access control occurs when an application fails to enforce restrictions on what authenticated users are allowed to do. This can lead to unauthorized access to other users' data, privilege escalation to admin roles, or performing actions outside the user's intended permissions — such as modifying or deleting resources they should not have access to.
What is the difference between authentication and authorization?
Authentication verifies identity (who are you?), while authorization determines permissions (what can you do?). A user can be properly authenticated but still access resources they shouldn't if authorization checks are missing or flawed. Many critical vulnerabilities arise from this distinction being overlooked.
How do you test for authorization vulnerabilities?
Test by accessing resources with different user roles, manipulating tokens or session cookies, changing IDs in API requests, and attempting to reach admin endpoints as a regular user. Tools like Autorize (Burp extension) automate this by replaying requests with different session tokens to detect missing authorization checks.

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