IIS7 Permissions Overview - ApplicationPoolIdentity

ApplicationPoolIdentity is actually the best practice to use in IIS7+. It is a dynamically created, unprivileged account. To add file system security for a particular application pool see IIS.net's "Application Pool Identities". The quick version:

If the application pool is named "DefaultAppPool" (just replace this text below if it is named differently)

Open Windows Explorer Select a file or directory. Right click the file and select "Properties" Select the "Security" tab Click the "Edit" and then "Add" button Click the "Locations" button and make sure you select the local machine. (Not the Windows domain if the server belongs to one.) Enter "IIS AppPool\DefaultAppPool" in the "Enter the object names to select:" text box. (Don't forget to change "DefaultAppPool" here to whatever you named your application pool.) Click the "Check Names" button and click "OK".

Remember to use the server's local name, not the domain name, when resolving the name

IIS AppPool\DefaultAppPool

https://i.stack.imgur.com/eTsyl.png

Giving access to the IIS AppPool\YourAppPoolName user may be not enough with IIS default configurations.

In my case, I still had the error HTTP Error 401.3 - Unauthorized after adding the AppPool user and it was fixed only after adding permissions to the IUSR user.

This is necessary because, by default, Anonymous access is done using the IUSR. You can set another specific user, the Application Pool or continue using the IUSR, but don't forget to set the appropriate permissions.

https://i.stack.imgur.com/Woroc.png

Credits to this answer: HTTP Error 401.3 - Unauthorized

On Windows Server 2008(r2) you can't assign an application pool identity to a folder through Properties->Security. You can do it through an admin command prompt using the following though:

icacls "c:\yourdirectory" /t /grant "IIS AppPool\DefaultAppPool":(R)

Part A: Configuring your Application Pool

Suppose the Application Pool is named 'MyPool' Go to 'Advanced Settings' of the Application Pool from the IIS Manager

Scroll down to 'Identity'. Trying to edit the value will bring up a dialog box. Select 'Built-In account' and under it, select 'ApplicationPoolIdentity'. A few lines below 'Identity', you should find 'Load User Profile'. This value should be set to 'True'.

Part B: Configuring your website

Website Name: SiteName (just an example) Physical Path: C:\Whatever (just an example) Connect as... : Application User (pass-through authentication) (The above settings can be found in 'Basic Settings' of the site in the IIS Manager) After configuring the basic settings, look for the 'Authentication' configuration under 'IIS' in the main console of the site. Open it. You should see an option for 'Anonymous Authentication'. Make sure it is enabled. Then right click and 'Edit...' it. Select 'Application Pool Identity'.

Part C: Configuring your folder

The folder in question is C:\Whatever

Go to Properties - Sharing - Advanced Sharing - Permissions, and tick 'Share this folder' In the same dialog box, you will find a button 'Permissions'. Click it. A new dialog box will open. Click 'Add'. A new dialog box 'Select Users or Groups' will open. Under 'From this location' make sure the name is the same as your local host computer. Then, under 'Enter the object names', type 'IIS AppPool\MyPool' and click 'Check Names' and then 'Ok' Give full sharing permissions for 'MyPool' user. Apply it and close the folder properties Open folder properties again. This time, go to Security - Advanced - Permission, and click Add. There will be an option 'Select a Principal' at the top, or some other option to choose a user. Click it. The 'Select Users or Groups' dialog box will open again. Repeat step 4. Give all or as many permissions you need to the 'MyPool' user. Check 'Replace all child object permissions..." and Apply and close.

You should now be able to use the browse the website

Top Answer from Jon Adams

Here is how to implement this for the PowerShell folks

$IncommingPath = "F:\WebContent"
$Acl = Get-Acl $IncommingPath
$Ar = New-Object  system.security.accesscontrol.filesystemaccessrule("IIS AppPool\DefaultAppPool","FullControl","ContainerInherit, ObjectInherit", "None", "Allow")
$Acl.SetAccessRule($Ar)
Set-Acl $IncommingPath $Acl

Just to add to the confusion, the (Windows Explorer) Effective Permissions dialog doesn't work for these logins. I have a site "Umbo4" using pass-through authentication, and looked at the user's Effective Permissions in the site root folder. The Check Names test resolved the name "IIS AppPool\Umbo4", but the Effective Permissions shows that the user had no permissions at all on the folder (all checkboxes unchecked).

I then excluded this user from the folder explicitly, using the Explorer Security tab. This resulted in the site failing with a HTTP 500.19 error, as expected. The Effective Permissions however looked exactly as before.

I fixed all my asp.net problems simply by creating a new user called IUSER with a password and added it the Network Service and User Groups. Then create all your virtual sites and applications set authentication to IUSER with its password.. set high level file access to include IUSER and BAM it fixed at least 3-4 issues including this one..

Dave