ASP.NET application having sysadmin privileges

[siarkazm]

Hi,

I have a following server configuration:
Windows 2003 Web Edition SP2
MS SQL Server Express 2005 SP2
SQL is running as NT AUTHORITY/NETWORK SERVICE
The only authentication method is Windows Authentication
Following logins are created on the SQL server:
BUILITIN\Administrators
NT AUTHORITY\SYSTEM
SERVNAME\SQLServer 2005MSSQLUser$SERVERNAME$MSSQLSERVER
Sa

I have an ASP.NET 2.0 application running on the same machine. The
application pool is configured to use same account as MS SQL (NT
AUTHORITY/NETWORK SERVICE). This account is not a login on the MS SQL
Server but the Web application have sysadmin access to the database! I
use following connection string in the web.config:
Data Source=.;Initial Catalog=DbName;Integrated Security=SSPI;Min Pool
Size=5;
I have also a backup server with almost identical configuration
(Windows 2003 Standard instead of Web Edition) and I must explicitly
configure login for NT AUTHORITY/NETWORK SERVICE to give the web app
access to the database.

Does anybody have a clue what is wrong with my server?

Cheers,

kuba