Information about XP 'Null Session Shares'
German version of this page
  What it is
A 'null session share' is a share which is accessible without login data, with 'null credentials'.
They are useful to give Windows services access to a share because Windows services are running in the 'Local System' account and can access this type of share only.

For accesses of interactive users it's not helpful because XP always tries the current logon data.


  Who to set up a null session share
First we need a usual share with permission for 'Everyone'. Then open the 'Local Security Policy':
Control Panel -> Administrative Tools -> Local Security Policy.
Here we set 'Network access: Let Everyone permissions apply to anonymous users' to 'Enabled'.
Then we add the name of our share to 'Network access: Shares that can be accessed anonymously'.
For a share 'Transfer' it would look so:

To take effect a restart is required.

On an NT4 Server there are different settings required, see here:


  Securitiy issues
Windows comes with some preset null session shares, so I think that an additional one is no problem.

The setting 'Network access: Let Everyone permissions apply to anonymous users' makes easier to access of course.


Last change: 26th July 2007

Uwe Sieber