Performing Content Security Policy Bypass

---
name: performing-content-security-policy-bypass
description: Use when analyze and bypass Content Security Policy implementations to
  achieve cross-site scripting by exploiting misconfigurations, JSONP endpoints, unsafe
  directives, and policy injection techniques. Use when analyzeing and bypass content
  security policy implementations to achieve cross-site.
domain: cybersecurity
tags:
- csp-bypass
- content-security-policy
- xss
- script-injection
- nonce-bypass
- jsonp
- policy-misconfiguration
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
category: cybersecurity
---

# Performing Content Security Policy Bypass

## Overview

Cybersecurity skill for performing content security policy bypass. Follows industry best practices and security standards.

## When to Use
**Trigger phrases:**
- "performing content security policy bypass"
- "Analyze and bypass Content Security Policy implementations to achieve cross-site"

- When XSS is found but execution is blocked by Content Security Policy
- During web application security assessments to evaluate CSP effectiveness
- When testing the robustness of CSP against known bypass techniques
- During bug bounty hunting where CSP prevents direct XSS exploitation
- When auditing CSP header configuration for security weaknesses


## 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
- Burp Suite for intercepting responses and analyzing CSP headers
- CSP Evaluator (Google) for automated policy analysis
- Understanding of CSP directives (script-src, default-src, style-src, etc.)
- Knowledge of CSP bypass techniques (JSONP, base-uri, object-src)
- Browser developer tools for CSP violation monitoring
- Collection of whitelisted domain JSONP endpoints

## Workflow

```python
# 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:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}
```

1. **Plan Operations** — Define objectives, scope, and success criteria for content security policy bypass operations.
2. **Prepare Environment** — Set up tools, access, and data sources required for content security policy bypass.
3. **Execute Core Workflow** — Perform the content security policy bypass operations following established procedures.
4. **Validate Results** — Verify that results meet quality standards and objectives.
5. **Report Findings** — Document results, observations, and recommendations.
6. **Follow Up** — Track remediation actions and verify fixes where applicable.

## Tools

- **Analysis Platform** — Data processing and visualization
- **Collaboration Tools** — Team coordination and knowledge sharing


## Process

1. **Reconnaissance** — Gather target information, identify attack surface, enumerate services
1. **Analysis/Exploitation** — Execute the technique, analyze results, document findings
1. **Reporting** — Document IOCs, write findings, provide remediation recommendations

## Verification

- [ ] All content security policy bypass procedures executed completely and documented
- [ ] Findings validated against multiple data sources
- [ ] False positives identified and filtered
- [ ] Results documented with evidence and timestamps
- [ ] Recommendations provided with risk-based prioritization

## Anti-Rationalization Table

| Rationalization | Reality |
|---|---|
| "We are too small to be targeted" | Automated attacks target everyone. Size does not matter. |
| "Security slows us down" | A breach slows you down 100x more. Build security in from the start. |
| "We will fix it after launch" | Vulnerabilities in production are exploited within hours. Fix before deploy. |