WebOTG-BAC-002 — Vertical Privilege Escalation & Role Enforcement Verification

1. Executive Summary & Scope

Vertical privilege escalation occurs when a standard unprivileged user can access functions or content reserved for administrative or privileged roles. This vulnerability arises when access controls are checked only on the client side (e.g. hiding UI buttons) or when backend controllers fail to enforce strict role-based access control (RBAC).

Standard Classification

OWASP Standard: OWASP Top 10 • Mapping: CWE-285 • Target Architecture: Public Web Systems & APIs

2. Threat Model & Attack Vectors

A regular registered user sends crafted HTTP POST requests to administrative endpoints (such as `/admin/users/delete` or `/api/v1/system/settings`) to gain administrative control over the entire system.

3. Code Analysis & Remediation Playbook

Vulnerable Implementation Pattern

// VULNERABLE: Only verifying authentication, omitting role check function handleUserDeletion() { if (!isset($_SESSION['user_id'])) { die("Please log in"); } // Deletes user without checking if current user has ROLE_ADMIN deleteUser($_POST['target_id']); }

Hardened Defense-in-Depth Implementation

// REMEDIATED: Centralized role hierarchy and permission assertion function handleUserDeletion() { $auth = require_auth_session(); if (!in_array('ROLE_ADMIN', $auth['roles'], true)) { http_response_code(403); log_security_alert("Vertical escalation attempt blocked", [ 'user' => $auth['user_id'], 'target_endpoint' => $_SERVER['REQUEST_URI'] ]); die(json_encode(['error' => 'Forbidden: Insufficient privileges'])); } deleteUser((int)$_POST['target_id']); }

4. Audit Verification Checklist & Pass Criteria

Verification Phase	Audit Test Description	Mandatory Passing Criteria
Unprivileged Endpoint Probing	Issue requests to all administrative URLs using regular user authorization tokens.	HTTP 403 Forbidden returned consistently for all non-admin requests.
Header Spoofing Resistance	Inject headers such as X-Forwarded-Role, X-Admin: true, or X-Original-User.	Backend ignores all unauthenticated client headers when computing access context.
Direct Controller Invocation	Test backend API endpoints directly via cURL without loading UI frontend.	All operations require valid, cryptographic session tokens possessing explicit roles.

WebOTG Application Security Directorate

Senior Security Auditor

WebOTG provides benchmark reference documentation, automated matrix evaluators, and security test harnesses for government digital platforms, WQMS architectures, and STQC compliance frameworks.