What is the risk of not using a trusted connection?
For example here is a scenario: I have created a very simple application which only has 4-5 lines of codes which uses an SQL connection with my connection string within web.config, and sends a select command to my database, and display results in an interface.
What are the security weakness here?
Edit:
I know trusted connection is related to authentication, what I wonder is I don't know how can the system be hacked if I don't use it ? (I will use my application at my company's servers and the application is a public application, so every company member can use it, so why do I need a trusted connection if it is a local company application ?)
To look at it the other way around, the main benefit of trusted connections is that you do not have to manage passwords in your application. If your application needs a password to connect to SQL Server, then where do you put the password (or connection string) so that the application user (or other developers, or sysadmins, or external consultants, etc.) cannot read it but you can still change it easily when required?
Passwords in files or the registry can often be read by users because when they run the application it has to retrieve the password, therefore the user needs access. Or a sysadmin or consultant has access to the filesystem where an application config file is. Obfuscating the password with some form of encryption is possible, but then you have to secure and manage the decryption key. Hard-coding the password in the application makes it difficult to change and also makes it highly likely that the password will be visible in the source control system, which is typically a relatively insecure system (in practice, if not by design). You can create a web service that the application gets the password from on startup but then you have to authenticate access to the service somehow.
Using trusted authentication avoids all of this completely by making the operating system responsible for authentication and unless you are a world-class security programmer, the odds are good that Windows provides a more reliable mechanism than you can create yourself.