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“CORS & Cross-Origin Resource Sharing” in Information Technology

41 questions across 3 technologies.

Information Technology

41 questions in 3 technologies

#QuestionTechnologyTopicLevel
1What does the WithMethods() CORS policy builder method control, and why restrict it instead of using AllowAnyMethod()? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingBeginner
2How would you set up a CORS policy that allows any subdomain of a given domain (like *.mycompany.com) using SetIsOriginAllowed? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingIntermediate
3What is CORS, and why do browsers enforce it? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingBeginner
4How do you configure a CORS policy in ASP.NET Core to allow requests from specific origins? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingIntermediate
5What does AllowCredentials() do in a CORS policy, and why can't it be combined with a wildcard origin? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingIntermediate
6Why must UseCors be positioned after UseRouting but before UseAuthorization in the ASP.NET Core middleware pipeline? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingIntermediate
7How do you configure CORS to allow requests only from multiple specific origins, such as both a production and staging frontend? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingIntermediate
8What is the difference between CORS and CSRF (Cross-Site Request Forgery), and how does CORS relate to (but not fully prevent) CSRF? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingIntermediate
9How do you troubleshoot a CORS error reported in browser developer tools, and what does the error message typically indicate? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingIntermediate
10What is a CORS preflight request, and when does the browser send one automatically? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingAdvanced
11How do you apply different CORS policies to different endpoints or controllers within the same application? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingAdvanced
12What security risks does an overly permissive CORS policy (like AllowAnyOrigin with credentials attempted, or reflecting the Origin header) introduce? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingAdvanced
13How does CORS interact with a reverse proxy or API gateway sitting in front of multiple backend microservices? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingAdvanced
14How do you configure CORS to expose custom response headers to client-side JavaScript using Access-Control-Expose-Headers? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingAdvanced
15How does CORS behave differently for requests made from a mobile app or server-to-server call compared to a browser-based web app? .NET › CORS & Cross-Origin Resource Sharing.NETCORS & Cross-Origin Resource SharingAdvanced
16How does the WithMethods() CORS policy builder method restrict cross-origin requests, and why is it preferable to AllowAnyMethod() for sensitive endpoints? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Intermediate
17What is CORS, and why does an ASP.NET Core API need to explicitly configure it for browser-based clients on a different origin? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Beginner
18Where must UseCors be positioned in the middleware pipeline relative to UseRouting and UseAuthorization, and why does this order matter? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Intermediate
19Why can't AllowCredentials() be combined with a wildcard origin (AllowAnyOrigin), and what does this mean for cookie-authenticated cross-origin APIs? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Intermediate
20How do you configure CORS to expose custom response headers (like X-Total-Count for pagination) to client-side JavaScript? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Intermediate
21What is the difference between CORS and CSRF protection, and why doesn't a strict CORS policy alone fully protect a cookie-authenticated endpoint? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Intermediate
22How would you troubleshoot a CORS error in browser developer tools, and what's the most common root cause? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Intermediate
23What is a CORS preflight request, and when does the browser automatically send one before the actual request? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Advanced
24How do you apply different CORS policies to different controllers or minimal API endpoint groups within the same application? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Advanced
25How would you configure CORS to allow any subdomain of a known domain (like *.mycompany.com) using SetIsOriginAllowed with custom matching logic? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Advanced
26How does CORS interact with an API gateway or reverse proxy sitting in front of multiple backend microservices? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Advanced
27How does CORS behave for requests made from a mobile app, server-to-server call, or a tool like curl/Postman, compared to a browser-based web app? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Advanced
28How do you configure CORS to allow multiple specific known origins simultaneously, such as production, staging, and local development? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Advanced
29How would you write an integration test verifying that a CORS policy correctly allows a specific origin and rejects an unauthorized one? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Advanced
30What security risk does dynamically reflecting the Origin header back as Access-Control-Allow-Origin introduce, and why is it a dangerous anti-pattern? ASP.NET Core › CORS (Cross-Origin Resource Sharing)ASP.NET CoreCORS (Cross-Origin Resource Sharing)Intermediate
31What is CORS middleware in Express, and how does the cors package simplify configuring Cross-Origin Resource Sharing? Node.js › Express & MiddlewareNode.jsExpress & MiddlewareIntermediate
32How do you configure CORS correctly when a Blazor WebAssembly app is hosted on a different origin than its backend API? ASP.NET Core › Blazor Integration with ASP.NET CoreASP.NET CoreBlazor Integration with ASP.NET CoreIntermediate
33How does JWT (JSON Web Token) authentication work at a high level in ASP.NET Core? .NET › Authentication & Authorization (Identity, JWT, OAuth).NETAuthentication & Authorization (Identity, JWT, OAuth)Intermediate
34How do refresh tokens work alongside short-lived access tokens, and why is this pattern used? .NET › Authentication & Authorization (Identity, JWT, OAuth).NETAuthentication & Authorization (Identity, JWT, OAuth)Intermediate
35What are the security risks of storing JWTs in browser localStorage versus HttpOnly cookies? .NET › Authentication & Authorization (Identity, JWT, OAuth).NETAuthentication & Authorization (Identity, JWT, OAuth)Intermediate
36How does cookie-based authentication work in ASP.NET Core, and when is it preferred over token-based authentication? ASP.NET Core › AuthenticationASP.NET CoreAuthenticationIntermediate
37How do you call an existing ASP.NET Core minimal API or controller endpoint from a Blazor WebAssembly component using HttpClient? ASP.NET Core › Blazor Integration with ASP.NET CoreASP.NET CoreBlazor Integration with ASP.NET CoreIntermediate
38Why can't browsers natively call gRPC services directly, and what is gRPC-Web, and how does it solve this? ASP.NET Core › gRPC ServicesASP.NET CoregRPC ServicesIntermediate
39How does ASP.NET Core determine the original client IP address and scheme (HTTP/HTTPS) when running behind a reverse proxy that terminates TLS and forwards requests, given the app only sees the proxy's connection? ASP.NET Core › Hosting Models: Kestrel, IIS & Reverse ProxiesASP.NET CoreHosting Models: Kestrel, IIS & Reverse ProxiesIntermediate
40What is the recommended standard order for common middleware in a typical ASP.NET Core Web API pipeline, and why? .NET › ASP.NET Core Middleware & Request Pipeline.NETASP.NET Core Middleware & Request PipelineAdvanced
41How does the OAuth 2.0 Authorization Code flow work, and why is it preferred over the deprecated Implicit flow for web applications? .NET › Authentication & Authorization (Identity, JWT, OAuth).NETAuthentication & Authorization (Identity, JWT, OAuth)Advanced