Description

Detects when ASP.NET cookies are explicitly configured with SameSite=None, which disables SameSite protection. This makes cookies vulnerable to cross-site request forgery (CSRF) attacks since they will be sent in cross-site requests, potentially allowing malicious sites to perform unauthorized actions.

Detection Strategy

• Identifies cookie configurations in ASP.NET applications where SameSiteMode is set to None

• Looks for specific assignments of SameSiteMode.None in cookie-related code

• Reports a vulnerability when a cookie's SameSite property is explicitly disabled through SameSiteMode.None

• Only flags issues within ASP.NET cookie configuration contexts

Vulnerable code example

using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;

public class CookieConfig
{
    public void ConfigureServices(IServiceCollection services)
    {
        // Vulnerable: Setting SameSite=None makes cookies vulnerable to CSRF attacks...

✅ Secure code example

using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;

public class CookieConfig
{
    public void ConfigureServices(IServiceCollection services)
    {
        // Secure: Set SameSite=Strict to prevent CSRF by blocking cross-site cookie transmission...