testing-cors-misconfiguration

name	testing-cors-misconfiguration
description	Identifying and exploiting Cross-Origin Resource Sharing misconfigurations that allow unauthorized cross-domain data access and credential theft during security assessments. Use when working with testing cors misconfiguration.
domain	cybersecurity
tags	["penetration-testing","cors","web-security","owasp","same-origin-policy","burpsuite"]
subdomain	web-application-security
version	1.0
author	oyi77
license	Apache-2.0
nist_csf	["PR.PS-01","ID.RA-01","PR.DS-10","DE.CM-01"]

Testing Cors Misconfiguration

Overview

Cybersecurity skill for testing cors misconfiguration. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "testing cors misconfiguration"

• "Identifying and exploiting Cross-Origin Resource Sharing misconfigurations that "

• During authorized penetration tests when assessing API endpoints for cross-origin access controls

• When testing single-page applications that make cross-origin API requests

• For evaluating whether sensitive data can be exfiltrated from a victim's browser session

• When assessing microservice architectures with multiple domains sharing data

• During security audits of applications using CORS headers for cross-domain communication

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

• Authorization: Written penetration testing agreement for the target
• Burp Suite Professional: For intercepting and modifying Origin headers
• Browser with DevTools: For observing CORS behavior in real browser context
• Attacker web server: For hosting CORS exploitation PoC pages
• curl: For manual CORS header testing
• Python HTTP server: For hosting exploit pages locally

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