Exploiting Insecure Deserialization

Exploiting Insecure Deserialization

Overview

Cybersecurity skill for exploiting insecure deserialization. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "exploiting insecure deserialization"

• "Identifying and exploiting insecure deserialization vulnerabilities in Java, PHP"

• During authorized penetration tests when applications process serialized data (cookies, API parameters, message queues)

• When identifying Java serialization markers (ac ed 00 05 / rO0AB) in HTTP traffic

• For testing PHP applications that use unserialize() on user-controlled input

• When evaluating .NET applications using BinaryFormatter, ObjectStateFormatter, or ViewState

• During security assessments of applications using pickle (Python), Marshal (Ruby), or YAML deserialization

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 with RCE testing scope
• ysoserial: Java deserialization exploit tool (git clone https://github.com/frohoff/ysoserial.git)
• ysoserial.net: .NET deserialization exploit tool (git clone https://github.com/pwntester/ysoserial.net.git)
• PHPGGC: PHP deserialization gadget chain generator (git clone https://github.com/ambionics/phpggc.git)
• Burp Suite Professional: With Java Deserialization Scanner extension
• Java Runtime: For running ysoserial
• Collaborator/interactsh: For out-of-band confirmation of code execution

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 insecure deserialization. Identify attack surface.
2. Vulnerability Identification — Enumerate potential insecure deserialization weaknesses using automated and manual techniques.
3. Exploit Development/Selection — Choose or develop exploits targeting identified insecure deserialization vulnerabilities.
4. Execution — Execute the insecure deserialization 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 insecure deserialization 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