Exploiting Server Side Request Forgery

Exploiting Server Side Request Forgery

Overview

Cybersecurity skill for exploiting server side request forgery. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "exploiting server side request forgery"

• "Identifying and exploiting SSRF vulnerabilities to access internal services, clo"

• During authorized penetration tests when the application fetches URLs provided by users (webhooks, URL previews, file imports)

• When testing cloud-hosted applications for access to instance metadata services

• For assessing PDF generators, screenshot services, or any feature that renders external content

• When evaluating microservice architectures for internal service access via SSRF

• During security assessments of APIs that accept URL parameters for data fetching

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 including SSRF testing scope
• Burp Suite Professional: With Collaborator for out-of-band detection
• interactsh: Open-source OOB interaction server (go install github.com/projectdiscovery/interactsh/cmd/interactsh-client@latest)
• SSRFmap: Automated SSRF exploitation framework (git clone https://github.com/swisskyrepo/SSRFmap.git)
• curl: For manual SSRF payload testing
• Knowledge of target infrastructure: Cloud provider (AWS, GCP, Azure), internal IP ranges

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

1. Reconnaissance — Gather information about the target related to server side request forgery. Identify attack surface.
2. Vulnerability Identification — Enumerate potential server side request forgery weaknesses using automated and manual techniques.
3. Exploit Development/Selection — Choose or develop exploits targeting identified server side request forgery vulnerabilities.
4. Execution — Execute the server side request forgery test in a controlled manner with proper authorization.
5. Post-Exploitation — Document the impact and extent of successful exploitation.
6. Reporting — Write detailed findings with reproduction steps, impact assessment, and remediation guidance.

Tools

• Vulnerability Scanner — Automated weakness identification
• Exploitation Framework — Controlled exploitation testing
• Reporting Tool — Findings documentation and tracking

Process

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

Verification

• All server side request forgery 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