dotnet-security-owasp
dotnet-security-owasp
OWASP Top 10 (2021) security guidance for .NET applications. Each category includes the vulnerability description, .NET-specific risk, mitigation code examples, and common pitfalls. This skill is the canonical owner of deprecated security pattern warnings (CAS, APTCA, .NET Remoting, DCOM, BinaryFormatter).
Out of scope: Authentication/authorization implementation -- API-level auth patterns (Identity, OAuth/OIDC, JWT, passkeys, CORS) -- see [skill:dotnet-api-security]. Blazor auth UI (AuthorizeView, CascadingAuthenticationState) -- see [skill:dotnet-blazor-auth]. Cloud-specific security services (Azure Key Vault, AWS Secrets Manager) -- cloud epics. Cryptographic algorithm selection and key management -- see [skill:dotnet-cryptography]. Configuration binding and Options pattern -- see [skill:dotnet-csharp-configuration].
Cross-references: [skill:dotnet-secrets-management] for secrets handling, [skill:dotnet-cryptography] for cryptographic best practices, [skill:dotnet-csharp-coding-standards] for secure coding conventions.
A01: Broken Access Control
Vulnerability: Users act outside their intended permissions -- accessing other users' data, elevating privileges, or bypassing access checks.
Risk in .NET: Missing [Authorize] attributes on controllers/endpoints, insecure direct object references (IDOR) where user IDs are taken from route parameters without ownership validation, and CORS misconfiguration allowing unintended origins.
Mitigation
More from wshaddix/dotnet-skills
csharp-wolverinefx
Build .NET applications with WolverineFX for messaging, HTTP services, and event sourcing. Use when implementing command handlers, message handlers, HTTP endpoints with WolverineFx.HTTP, transactional outbox patterns, event sourcing with Marten, CQRS architectures, cascading messages, batch message processing, or configuring transports like RabbitMQ, Azure Service Bus, or Amazon SQS.
374modern-csharp-coding-standards
Write modern, high-performance C# code using records, pattern matching, value objects, async/await, Span<T>/Memory<T>, and best-practice API design patterns. Emphasizes functional-style programming with C# 12+ features. Use when writing new C# code or refactoring existing code, designing public APIs for libraries or services, optimizing performance-critical code paths, or building async/await-heavy applications.
364testcontainers
Patterns for using Testcontainers in .NET integration tests to spin up real dependencies like databases and message queues. Use when writing integration tests that require real databases, testing with message brokers like RabbitMQ or Kafka, or isolating test dependencies with Docker containers.
357logging-observability
Production-grade logging and observability patterns for ASP.NET Core Razor Pages. Covers structured logging with Serilog, correlation IDs, health checks, request logging, OpenTelemetry integration, and diagnostic best practices. Use when setting up structured logging in ASP.NET Core applications, implementing distributed tracing with OpenTelemetry, or configuring health checks and observability.
357microsoft-extensions-dependency-injection
Dependency injection patterns and best practices using Microsoft.Extensions.DependencyInjection for .NET applications. Use when configuring DI containers in .NET, choosing between service lifetimes (Singleton, Scoped, Transient), or implementing decorator patterns and service interception.
354validation-patterns
Comprehensive validation patterns for ASP.NET Core applications. Covers FluentValidation integration, DataAnnotations, IValidatableObject, IValidateOptions<T>, MediatR pipeline behavior, and client-side validation. Use when implementing validation in ASP.NET Core applications, setting up FluentValidation, creating custom validators, configuring options validation, or implementing cross-field validation.
353