Fix SQL injection in C# and ASP.NET Core
========================================

Keep CommandText constant and bind values: write $name placeholders and call
command.Parameters.AddWithValue("$name", name). Never interpolate request data
into CommandText. Column names and ASC/DESC cannot be parameters, so look the
requested sort up in a Dictionary of allowed SQL fragments and return 400 for
anything else.

Page: https://softwaresecurity.com/fix/sql-injection/csharp-aspnetcore/

What is in this archive
-----------------------
sql-injection/csharp-aspnetcore/   the project: three implementations of the same code and one test suite
  src/Orders/impl/VulnerableOrderRepository.cs   (vulnerable)
  src/Orders/impl/FixedOrderRepository.cs   (fixed)
  src/Orders/impl/WrongOrderRepository.cs   (a plausible fix that still fails)
run-all.mjs   runs the tests in all three modes and checks the results (Node.js only)
LICENSE-CODE.txt

Run it
------
  Tested with .NET 10.0.12 (SDK 10.0.112). run-all.mjs needs Node.js 22 or
  later. Supported versions: https://softwaresecurity.com/fix/versions/

  From the sql-injection/csharp-aspnetcore folder, install the dependencies once
  (this needs network access):

    dotnet restore tests/Orders.Tests --locked-mode

  Then run the tests. IMPL chooses the implementation the tests load:

    # every test passes
    IMPL=fixed dotnet test --project tests/Orders.Tests --no-restore --results-directory reports --report-xunit-junit --report-xunit-junit-filename junit.xml
    # an exploit test fails
    IMPL=vulnerable dotnet test --project tests/Orders.Tests --no-restore --results-directory reports --report-xunit-junit --report-xunit-junit-filename junit.xml
    # a test fails
    IMPL=wrong dotnet test --project tests/Orders.Tests --no-restore --results-directory reports --report-xunit-junit --report-xunit-junit-filename junit.xml

  The JUnit report is written to reports/junit.xml. To run all three modes and
  check the results in one step, run the harness from this top folder (it needs
  only Node.js; --install runs the install step first):

    node run-all.mjs --install sql-injection/csharp-aspnetcore
    node run-all.mjs sql-injection/csharp-aspnetcore

Verified
--------
  11 October 2026 on macOS 27.0 (Darwin 27.0.0, arm64), with dotnetSdk 10.0.112,
  runtime 10.0.12, Microsoft.Data.Sqlite 10.0.12, xunit.v3 4.0.2. Versions and
  results hold for that date: run the tests with your own versions before
  relying on the fix.

Licence
-------
  The code is MIT licensed (LICENSE-CODE.txt). The page text is CC BY 4.0.
