<PackageReference Include="System.Security.Permissions" Version="10.0.1" />

System.Data.SqlClient.SqlClientPermission

public sealed class SqlClientPermission : DBDataPermission
Enables the .NET Framework Data Provider for SQL Server to help make sure that a user has a security level sufficient to access a data source.
namespace System.Data.SqlClient { public sealed class SqlClientPermission : DBDataPermission { public SqlClientPermission(); public SqlClientPermission(PermissionState state); public SqlClientPermission(PermissionState state, bool allowBlankPassword); } }