Web application security in C#

C# developers working on Web applications

• Getting familiar with essential cyber security concepts
• Understanding Web application security issues
• Detailed analysis of the OWASP Top Ten elements
• Putting Web application security in the context of C#
• Going beyond the low hanging fruits
• Managing vulnerabilities in third party components
• Identify vulnerabilities and their consequences
• Learn the security best practices in C#
• Input validation approaches and principles

General C# and Web development

Day 1:

• Cyber security basics
  • What is security?
  • Threat and risk
  • Cyber security threat types
  • Consequences of insecure software
• The OWASP Top Ten
  • The OWASP Top 10
  • A1 – Injection
    • Injection principles
    • Injection attacks
    • SQL injection
      • SQL injection basics
      • Lab – SQL injection
      • Attack techniques
      • Content-based blind SQL injection
      • Time-based blind SQL injection
    • SQL injection best practices
      • Input validation
      • Parameterized queries
      • Lab – Using prepared statements
      • Case study – Hacking Fortnite accounts
    • Code injection
      • OS command injection
        • Lab – Command injection
        • OS command injection best practices
        • Avoiding command injection with the right APIs
        • Lab – Command injection best practices
  • A2 – Broken Authentication
    • Authentication
      • Authentication basics
      • Multi-factor authentication
      • Authentication weaknesses
      • Case study – PayPal 2FA bypass
    • Password management
      • Inbound password management
        • Storing account passwords
        • Password in transit
        • Lab – Is just hashing passwords enough?
        • Dictionary attacks and brute forcing
        • Salting
        • Adaptive hash functions for password storage
        • Lab – Using adaptive hash functions in C#
        • Password policy
          • NIST authenticator requirements for memorized secrets
        • Case study – The Ashley Madison data breach
          • The dictionary attack
          • The ultimate crack
          • Exploitation and the lessons learned
        • Password database migration
          • (Mis)handling null passwords

Day 2:

The OWASP Top Ten

• A2 – Broken Authentication (continued)
  • Session management
    • Session management essentials
    • Why do we protect session IDs – Session hijacking
    • Session fixation
    • Session ID best practices
• A3 – Sensitive Data Exposure
  • Information exposure
  • Exposure through extracted data and aggregation
  • Case study – Strava data exposure
• A4 – XML External Entities (XXE)
  • DTD and the entities
  • Entity expansion
  • External Entity Attack (XXE)
    • File inclusion with external entities
    • Server-Side Request Forgery with external entities
    • Lab – External entity attack
    • Case study – XXE vulnerability in SAP Store
    • Preventing XXE
    • Lab – Prohibiting DTD
• A5 – Broken Access Control
  • Access control basics
  • Failure to restrict URL access
  • Confused deputy
    • Insecure direct object reference (IDOR)
    • Lab – Insecure Direct Object Reference
    • Authorization bypass through user-controlled keys
    • Case study – Authorization bypass on Facebook
    • Lab – Horizontal authorization
  • File upload
    • Unrestricted file upload
    • Good practices
    • Lab – Unrestricted file upload
• A7 – Cross-site Scripting (XSS)
  • Cross-site scripting basics
  • Cross-site scripting types
    • Persistent cross-site scripting
    • Reflected cross-site scripting
    • Client-side (DOM-based) cross-site scripting
  • Lab – Stored XSS
  • Lab – Reflected XSS
  • Case study – XSS in Fortnite accounts
  • XSS protection best practices
    • Protection principles – escaping
    • XSS protection APIs
    • Request validation in ASP.NET
    • Further XSS protection techniques
    • Lab – XSS fix / stored
    • Lab – XSS fix / reflected
    • Additional protection layers
    • Client-side protection principles
• A8 – Insecure Deserialization
  • Serialization and deserialization challenges
  • Integrity – deserializing untrusted streams
  • Integrity – deserialization best practices
  • Property Oriented Programming (POP)
    • Creating payload
    • Summary – POP best practices
    • Lab – Creating a POP payload
    • Lab – Using the POP payload
• A9 – Using Components with Known Vulnerabilities
  • Using vulnerable components
  • Assessing the environment
  • Hardening
  • Untrusted functionality import
  • Importing JavaScript
  • Lab – Importing JavaScript
  • Case study – The British Airways data breach
  • Vulnerability management
    • Patch management
    • Vulnerability databases
    • Lab – Finding vulnerabilities in third-party components

Day 3:

• The OWASP Top Ten
  • Web application security beyond the Top Ten
    • Client-side security
    • Tabnabbing
    • Lab – Reverse tabnabbing
    • Frame sandboxing
      • Cross-Frame Scripting (XFS) attack
      • Lab – Clickjacking
      • Clickjacking beyond hijacking a click
      • Clickjacking protection best practices
      • Lab – Using CSP to prevent clickjacking
• API security
  • Input validation
    • Input validation principles
      • Blacklists and whitelists
      • Data validation techniques
      • Lab – Input validation
      • What to validate – the attack surface
      • Where to validate – defense in depth
      • When to validate – validation vs transformations
      • Output sanitization
      • Encoding challenges
      • Unicode challenges
      • Lab – Encoding challenges
      • Validation with regex
      • Regular expression denial of service (ReDoS)
      • Lab – ReDoS in C#
      • Dealing with ReDoS
    • Integer handling problems
      • Representing signed numbers
      • Integer visualization
      • Integer overflow
      • Lab – Integer overflow
      • Signed / unsigned confusion
      • Case study – The Stockholm Stock Exchange
      • Lab – Signed / unsigned confusion
      • Integer truncation
      • Best practices
        • Upcasting
        • Precondition testing
        • Postcondition testing
        • Integer handling in C#
        • Lab – Checked arithmetics
    • Unsafe reflection
      • Reflection without validation
      • Lab – Unsafe reflection
  • Code quality
    • Code quality and security
    • Data handling
      • Initialization and cleanup
        • Class initialization cycles
        • Lab – Initialization cycles
    • Object oriented programming pitfalls
      • Inheritance and overriding
      • Mutability
        • Lab – Mutable object
        • Readonly collections
• Wrap up
  • Secure coding principles
    • Principles of robust programming by Matt Bishop
    • Secure design principles of Saltzer and Schröder
  • And now what?
    • Software security sources and further reading
    • .NET and C# resources