exploiting-broken-function-level-authorization

name	exploiting-broken-function-level-authorization
description	Use when tests APIs for Broken Function Level Authorization (BFLA) vulnerabilities where regular users can invoke administrative functions or access privileged API endpoints by directly calling them. The tester identifies admin and privileged endpoints, then attempts to access them with regular user credentials by manipulating HTTP methods, URL paths, and request parameters. Maps to OWASP API5:2023 Broken Function Level Authorization.
domain	cybersecurity
tags	["api-security","owasp","authorization","bfla","privilege-escalation","access-control"]
subdomain	api-security
version	1.0.0
author	oyi77
license	Apache-2.0
nist_csf	["PR.PS-01","ID.RA-01","PR.DS-10","DE.CM-01"]

Exploiting Broken Function Level Authorization

Overview

Cybersecurity skill for exploiting broken function level authorization. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "exploiting broken function level authorization"

• "Tests APIs for Broken Function Level Authorization (BFLA) vulnerabilities where "

• Testing whether regular users can access administrative API endpoints by direct URL access

• Assessing APIs for vertical privilege escalation where users can invoke functions above their role

• Evaluating if API gateways and middleware consistently enforce function-level access controls

• Testing role-based access control (RBAC) implementation across all API endpoints and HTTP methods

• Validating that API documentation does not expose admin endpoint paths that lack authorization

Do not use without written authorization. BFLA testing involves attempting to execute administrative functions with unauthorized credentials.

When NOT to Use

• When you lack proper authorization for testing
• For production systems without change management
• When the task requires legal or compliance expertise beyond technical scope

Prerequisites

• Written authorization specifying target API and administrative functions in scope
• Test accounts at multiple privilege levels: regular user, moderator, admin, super-admin
• API documentation (OpenAPI/Swagger spec) that may list admin endpoints
• Burp Suite Professional for request interception and manipulation
• Python 3.10+ with requests library
• Knowledge of common admin endpoint naming conventions

Workflow

# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs() -> :
     {k: re.findall(v, text)  k, v  IOC_PATTERNS.items()}