Web application security in C#

3 days
On-site or online

31 Labs


10 Case Studies


C# developers working on Web applications


General C# and Web development

Standards and references

OWASP, CWE and Fortify Taxonomy

Group size

12 participants


  • Cyber security basics
  • The OWASP Top Ten
  • API security
  • Wrap up

What you'll have learned

  • 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


Your Web application written in C# works as intended, so you are done, right? But did you consider feeding in incorrect values? 16Gbs of data? A null? An apostrophe? Negative numbers, or specifically -1 or -231? Because that’s what the bad guys will do – and the list is far from complete.

Handling security needs a healthy level of paranoia, and this is what this course provides: a strong emotional engagement by lots of hands-on labs and stories from real life, all to substantially improve code hygiene. Mistakes, consequences, and best practices are our blood, sweat and tears.

The curriculum goes through the common Web application security issues following the OWASP Top Ten but goes far beyond it both in coverage and the details.All this is put in the context of C#, and extended by core programming issues, discussing security pitfalls of the C# language and the ASP.NET framework.

So that you are prepared for the forces of the dark side.

So that nothing unexpected happens.


They said about us

Class was great!

Pace of the course was just right. Favourite part was reviewing of the ways to hack XML and JSON, and the ways to prevent that. Pretty relevant to what I am currently working on.

Employee at a Global Insurance Group , April, 2019

Norwood, MA, USA

Table of contents

  • Cyber security basics
  • 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
          • 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
  • 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
  • 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


3 days Session Price

2250 EUR / person

  • Live, instructor led classroom training
  • Discussion and insight into the hacker’s mindset
  • Hands-on practice using case studies based on high-profile hacks and live lab exercises
Customized Course

Tailor a course to your preferences

  • Send us a brief description of your business’s training needs
  • Include your contact information
  • One of our colleagues will be in touch to schedule a free 45 minute pre-training consultation


Interested in the trainings but still have some questions? Curious about how you can customize a training for your team? Send us a message and a team member will be in touch within 24 hours.

This field is required

This field is required

Send us your phone number if you prefer to discuss further on a call

This field is required

This field is required

This field is required

This field is required