Accessing a {null-keyword-link}[{null-keyword}] value will always throw a https://learn.microsoft.com/en-us/dotnet/api/system.nullreferenceexception[NullReferenceException] most likely causing an abrupt program termination.
Such termination might expose sensitive information that a malicious third party could exploit to, for instance, bypass security measures.
=== Exceptions
In the following cases, the rule does not raise:
==== Extensions Methods
Calls to extension methods can still operate on `{null-keyword}` values.
https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/attributes/nullable-analysis[Nullable analysis attributes] enable the developer to annotate methods with information about the null-state of its arguments. Thus, potential `{null-keyword}` values validated by one of the following attributes will not raise:
It is important to note those attributes are only available starting .NET Core 3. As a workaround, it is possible to define those attributes manually in a custom class:
A value validated with https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.debug.assert[Debug.Assert] to not be `{null-keyword}` is safe to access.
(The attribute is interpreted the same as the https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.codeanalysis.notnullattribute[NotNullAttribute])
