Penetration Testing

A professional penetration test follows a structured lifecycle, not random attacks. The key phases are:

• Reconnaissance: Gathering intelligence on the target (passive/active).
• Scanning & Enumeration: Using tools to identify live hosts, open ports, services, and vulnerabilities.
• Gaining Access: Exploiting identified vulnerabilities to breach the system.
• Maintaining Access: Establishing persistence to simulate an advanced persistent threat (APT).
• Analysis & Reporting: Documenting findings, risks, and actionable remediation steps.

A formal agreement defining the scope, boundaries, and authorization for the test. It specifies:

• Authorized Targets: Which systems, networks, or applications can be tested.
• Testing Windows: Approved dates and times for active testing.
• Permitted Techniques: Which tools and attack vectors are allowed (e.g., social engineering, DoS).
• Communication Protocols: How and when to report critical findings. The RoE is crucial for legal protection and test effectiveness.

Tests are categorized by the tester's prior knowledge of the system.

• Black Box Testing: The tester has no internal knowledge, simulating an external attacker. This tests detection and response capabilities.
• White Box Testing: The tester has full knowledge (e.g., source code, architecture). This is a thorough audit to find deep-seated vulnerabilities.
• Gray Box Testing: A hybrid approach where the tester has limited knowledge (e.g., user-level credentials), simulating an insider threat or an attacker with leaked information.

The core technical phase where vulnerabilities are actively leveraged.

• Exploitation: Using a specific exploit (a piece of code or sequence of commands) to take advantage of a vulnerability, such as gaining a shell or escalating privileges.
• Post-Exploitation: Actions taken after initial access, including:
  • Lateral Movement: Pivoting to other systems on the network.
  • Privilege Escalation: Gaining higher-level permissions (e.g., root/admin).
  • Data Exfiltration: Demonstrating the ability to steal sensitive information.

The final and most critical deliverable is a detailed report. It translates technical findings into business risk. A quality report includes:

• Executive Summary: High-level business impact and risk rating.
• Technical Findings: Detailed evidence for each vulnerability, including steps to reproduce, screenshots, and packet captures.
• Risk Assessment: CVSS scores and business context for each finding.
• Remediation Guidance: Clear, actionable steps to fix each issue, often prioritized by risk.

Penetration testing is not a one-time event but part of a continuous security validation program. It is often mandated by regulations and standards, including:

• PCI DSS: Requires annual pen tests for organizations handling card data.
• ISO 27001: Recommends periodic security testing.
• SOC 2: Uses pen tests as evidence of security controls. Modern programs integrate automated vulnerability scanning with regular manual pen tests for a layered defense.

The primary focus in blockchain security, targeting the logic of smart contracts on platforms like Ethereum. Testers simulate attacks to find flaws such as:

• Reentrancy vulnerabilities (e.g., The DAO hack)
• Integer overflows/underflows
• Access control issues and improper authorization
• Logic errors in financial math or state management Tools like static analyzers (Slither, MythX) and fuzzers (Echidna) are used alongside manual review.

Assesses the resilience of the underlying blockchain network and its node infrastructure. This includes testing for:

• Consensus attacks: 51% attacks, selfish mining, long-range attacks
• RPC endpoint security: Exposed APIs that could allow remote code execution or denial-of-service
• Peer-to-peer (P2P) network exploits: Eclipse attacks, transaction malleability
• Validator/client vulnerabilities (e.g., in Geth, Prysm, or Solana validators)

Targets the user-facing components that interact with the blockchain, which are common attack vectors. Tests evaluate:

• Web application security: XSS, CSRF, and injection flaws in dApp frontends
• Wallet connection exploits: Malicious transaction signing prompts, phishing via malicious domains
• Oracle manipulation attempts through the frontend
• Meta-transaction and gas sponsorship relay vulnerabilities

A unique category for DeFi, probing the financial incentives and mechanisms that could be gamed. Testers model scenarios like:

• Flash loan attacks: Exploiting uncollateralized loans to manipulate oracle prices or drain liquidity pools
• Governance attacks: Accumulating voting power to pass malicious proposals
• MEV (Maximal Extractable Value) exploitation: Front-running, sandwich attacks, and time-bandit attacks
• Liquidity pool arbitrage and impermanent loss triggers

The structured process typically follows standards like the OWASP Testing Guide and involves:

1. Reconnaissance & Planning: Mapping the attack surface (contracts, APIs, frontends).
2. Automated Scanning: Using tools like Slither, Mythril, and Certora for formal verification.
3. Manual Exploitation & Analysis: Expert manual review and exploit development.
4. Reporting & Remediation: Delivering a detailed report with CVSS scores, proof-of-concept code, and mitigation advice.

A structured penetration test follows a defined lifecycle: Reconnaissance (information gathering), Scanning & Enumeration (identifying live systems and services), Gaining Access (exploiting vulnerabilities), Maintaining Access (persistence), and Analysis & Reporting (documenting findings). For smart contracts, this includes static/dynamic analysis and manual code review.

Testing targets specific, high-risk attack vectors unique to decentralized applications:

• Reentrancy: Unauthorized recursive calls to withdraw funds.
• Logic Errors: Flaws in business logic, access control, or arithmetic.
• Oracle Manipulation: Exploiting price feed dependencies.
• Front-running: Benefiting from prior knowledge of pending transactions. Tools like Slither (static analysis) and Foundry's forge (fuzzing) are commonly used.

The scope of tester knowledge defines the approach:

• Black Box Testing: The tester has no internal knowledge of the system, simulating an external attacker. This tests real-world exploitability.
• White Box Testing: The tester has full access to source code, architecture diagrams, and credentials. This allows for deep, comprehensive analysis of logic flaws and is standard for smart contract audits.

The primary deliverable is a detailed technical report that classifies findings by severity (Critical, High, Medium, Low, Informational). Each finding includes: a vulnerability description, proof-of-concept exploit code, impact assessment, and remediation recommendations. A reputable audit is a key trust signal for users and investors.

Pen testing is not a silver bullet. Key limitations and practices include:

• Point-in-Time Assessment: It reflects the system's security at a specific moment; continuous monitoring is needed.
• Scope Limitations: Issues outside the agreed scope (e.g., underlying blockchain consensus) are not tested.
• Best Practice: Combine automated tools with expert manual review, test on a forked mainnet environment, and re-audit after major code changes.

A systematic review of a system to identify, quantify, and prioritize security vulnerabilities. Unlike a penetration test, it typically does not involve active exploitation. It is a foundational step that informs the scope of a penetration test.

• Automated Scanning: Uses tools to detect known vulnerabilities in code and configurations.
• Passive Analysis: Reviews architecture, smart contract code, and access controls without active attacks.

A full-scope, adversarial simulation designed to test an organization's detection and response capabilities. A Red Team acts like a real-world attacker, using stealth and advanced techniques over an extended period.

• Objective-Based: Goals mimic real attackers (e.g., exfiltrate specific data, compromise a validator key).
• Broad Scope: Encompasses social engineering, physical security, and multiple attack vectors beyond technical systems.

A comprehensive, in-depth examination of a system's security posture, often performed manually by experts. For blockchains, this focuses heavily on smart contract code and protocol logic.

• Manual Code Review: Line-by-line analysis for logic flaws, economic vulnerabilities, and gas optimization issues.
• Formal Verification: Uses mathematical methods to prove the correctness of code against a specification.

A structured process to identify, quantify, and address the security risks to a system before it is built or deployed. It shapes the defensive design and informs penetration test scenarios.

• STRIDE Framework: Classifies threats as Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, or Elevation of Privilege.
• Architectural Focus: Analyzes data flows, trust boundaries, and potential attack surfaces.

The planned methodology for handling a security breach or attack. While penetration testing is proactive, incident response is reactive, focusing on containment, eradication, and recovery.

• Playbooks: Pre-defined steps for different attack scenarios (e.g., oracle manipulation, bridge exploit).
• Post-Mortem Analysis: A critical review after an incident to improve defenses and update penetration testing strategies.