Web application security in C#

3 days
On-site or online

27 Labs


13 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 2021
  • Wrap up

What you will learn

  • Getting familiar with essential cyber security concepts
  • Understanding how cryptography supports security
  • Learning how to use cryptographic APIs correctly in C#
  • 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


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 -2^31? 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 2021
    • A01 – Broken Access Control
      • Access control basics
      • Confused deputy
        • Insecure direct object reference (IDOR)
        • Path traversal
        • Lab – Insecure Direct Object Reference
        • Path traversal best practices
        • 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
    • A02 – Cryptographic Failures
      • Information exposure
        • Exposure through extracted data and aggregation
        • Case study – Strava data exposure
      • Cryptography for developers
        • Cryptography basics
        • Crypto APIs in C#
        • Elementary algorithms
          • Random number generation
            • Pseudo random number generators (PRNGs)
            • Cryptographically secure PRNGs
            • Weak and strong PRNGs
            • Using random numbers in C#
            • Lab – Using random numbers in C#
            • Case study – Equifax credit account freeze
          • Hashing
            • Hashing basics
            • Hashing in C#
            • Lab – Hashing in C#
        • Confidentiality protection
          • Symmetric encryption
            • Block ciphers
            • Modes of operation
            • Modes of operation and IV – best practices
            • Symmetric encryption in C#
            • Symmetric encryption in C# with streams
            • Lab – Symmetric encryption in C#
          • Asymmetric encryption
            • The RSA algorithm
              • Using RSA – best practices
              • RSA in C#
          • Combining symmetric and asymmetric algorithms
  • The OWASP Top Ten 2021
    • A03 – 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
          • Case study – Command injection via ping
      • HTML injection – 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
          • Further XSS protection techniques
          • Lab – XSS fix / stored
          • Lab – XSS fix / reflected
          • Additional protection layers – defense in depth
    • A04 – Insecure Design
      • The STRIDE model of threats
      • Secure design principles of Saltzer and Schroeder
        • Economy of mechanism
        • Fail-safe defaults
        • Complete mediation
        • Open design
        • Separation of privilege
        • Least privilege
        • Least common mechanism
        • Psychological acceptability
      • Client-side security
        • Frame sandboxing
          • Cross-Frame Scripting (XFS) attacks
          • Lab – Clickjacking
          • Clickjacking beyond hijacking a click
          • Clickjacking protection best practices
          • Lab – Using CSP to prevent clickjacking
    • A05 – Security Misconfiguration
      • Configuration principles
      • XML entities
        • 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
  • The OWASP Top Ten 2021
    • A06 – Vulnerable and Outdated Components
      • Using vulnerable components
      • Assessing the environment
      • Hardening
      • Untrusted functionality import
      • Vulnerability management
    • A07 – Identification and Authentication Failures
    • A08 – Software and Data Integrity Failures
      • Integrity protection
        • Message Authentication Code (MAC)
          • Calculating HMAC in C#
          • Lab – Calculating MAC in C#
        • Digital signature
          • Digital signature with RSA
          • Elliptic Curve Cryptography
            • ECC basics
            • Digital signature with ECC
          • Digital signature in C#
            • Lab – Digital signature with ECDSA in C#
      • Subresource integrity
        • Importing JavaScript
        • Lab – Importing JavaScript
        • Case study – The British Airways data breach
      • Insecure deserialization
        • Serialization and deserialization challenges
        • Integrity – deserializing untrusted streams
        • Integrity – deserialization best practices
        • Look ahead deserialization
        • Property Oriented Programming (POP)
          • Creating a POP payload
          • Lab – Creating a POP payload
          • Lab – Using the POP payload
          • Summary – POP best practices
    • A09 – Security Logging and Monitoring Failures
      • Logging and monitoring principles
      • Insufficient logging
      • Case study – Plaintext passwords at Facebook
      • Logging best practices
      • Monitoring best practices
    • A10 – Server-side Request Forgery (SSRF)
      • Server-side Request Forgery (SSRF)
      • Case study – SSRF and the Capital One breach
  • Wrap up
    • Secure coding principles
      • Principles of robust programming by Matt Bishop
    • 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
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