We recently had to change a domain admin password due to a security issue. As a result, on our prod web server, we're seeing a large number of Event ID 4625 errors showing up in our security log associated with an IIS App Pool. We're on Windows 2012 R2/IIS 8.5; ASP.NET 2.0 & 4.0 are installed on the system.
The interesting piece is that the App Pool in question never used the domain admin account as its Identity. It has always used the out of the box ApplicationPoolIdentity. I should also note that the server was logged off using that affected user well prior to the password change & a new account is now used to administer the server.
The server itself though was in fact built using the affected domain admin account. All roles/features were added while logged in as the aforementioned account. With this in mind, no services are running as the account, ie World Wide Web Publishing Service/IIS Admin service. They're running as Local System & always have.
No functionality has been compromised, everything is operating normally on the web server. The issue is that our tech services team is receiving constant notifications from their account monitoring software regarding the bad logon attempts & it is impeding their operations. Full disclosure... We haven't had an opportunity to reboot the server yet since its production, we will be doing that tonight.
The problem seems to be relegated to the root of the site, the \wwwroot folder. Segregating only the root app to its own app pool/turning off the pool is not an option since it services file system requests. We've tried explicitly setting the identity on the affected app pool to use Local Service as well as a regular domain user. The issue persists regardless:
So naturally, our hope is that the reboot takes care of it... Perhaps the old password is stuck in a kerberos cache, but it's just strange since this app pool never used the ID as its identity, that it continues to show up.
We had a virtual directory that was using the ID in order to reach out to a CIFS share on the network. Once we changed that, the error ceased.
Related
CONTEXT
My client has an ASP.NET web application running in IIS 10 on Windows Server 2016. The web application needs to access files on network shares on different servers in a WORKGROUP environment. So, I created the same local user account on all servers, set the password to all the local user accounts to be the same, granted said user with full control permissions to the network shares, and reconfigured the IIS application pool to run under the identity of the aforementioned local user account. There is also a custom Windows service running under the same local user account for the same reason: to access files on remote network shares. All of this works fine. The web application and the Windows service can successfully access files from the network shares residing on servers other than the server on which IIS and the custom Windows service are both running.
ISSUE
However, there is a feature in the web application when an authorized user modifies a particular validation matrix record, it triggers a custom command sent to the aforementioned Windows service to cause the service to update its in-memory copy of the validation matrix. This worked fine when the IIS application pool was running under the built-in ApplicationPoolIdentity which apparently has permissions to interact with Windows services. But, the feature fails when the IIS application pool is running under the identity of the aforementioned local user account. The message in the exception is: Cannot open {SERVICE_NAME} service on computer '.'. Again, the Windows service and IIS are running on the same server. And recall that the Windows service is running under the same local user account as the IIS application pool identity.
QUESTION
How do I grant permissions to the local user account to allow said account the ability to issue the custom command to the Windows service from within the ASP.NET web application?
RESOLUTION ATTEMPTS
I've tried using subinacl.exe in an attempt to grant the necessary access but never got it to do anything other than to indicate Done 0, Modified 0, Failed 0, Syntax errors 0. I'm using version 4.2.1.1604 and executing it from an Administrative Command Prompt. The syntax I used was:
subinacl /service customServiceName /grant=localUserAccount
and the result is below
+service customServiceName
/grant=localUserAccount
Elapsed Time: 00 00:00:00
Done: 0, Modified 0, Failed 0, Syntax errors 0
I also tried /grant=localUserAccount=U and /grant=localUserAccount=F but to no avail ... same results as shown above.
I admittedly am not familiar with subinacl.exe and I saw somewhere that someone indicated earlier versions of subinacl.exe are buggy and suggested using version 5.2.3790.1180 which I cannot find. Result: failed.
I have added the local user account to the Administrators group on the server where IIS and the Windows service are running. Result: failed. CORRECTION 02/13/2023: This succeeded but required a server reboot for it to take effect. To be clear, I do NOT want to permanently add this user to the Administrators group. This was simply a test. As far as the server reboot being required for this to take effect is concerned, I tried recycling the application pool in IIS, restarting the Windows service of interest, and restarting the World Wide Web Publishing Service but no joy. Only a server reboot caused the addition of the local user account to the Administrators group to take effect from the standpoint of said local user having permissions to send a custom command to the Windows service from within the web application. I absolutely am inclined to believe that there is a better way to achieve the desired end without adding the local user account to the Administrators group. Surely someone else before me has encountered this and solved it.
The local user account is already set up in the Local Security Policy with the ability to "Log on as a service".
I have reconfigured the IIS application pool identity to NETWORK SERVICE and granted NETWORK SERVICE full control permissions to the network shares (which are on a different server in a WORKGROUP environment, not a domain environment). In this configuration, the feature to update the Windows service works, but access to the network shares is denied ... likely because NETWORK SERVICE is a built-in local account [with no password?? not sure on this] and does not behave the same as a "regular" local user account.
So, I have a catch-22 that has me stumped. I would be grateful for any insight on this dilemma.
Cheers!
Wondering if you can help me here, been battering away at this for days now.
i have an IIS site with windows authentication installed, which is working exactly the way it should do. This particular IIS Server houses approx 6 other sites so i have create a new Site called Helpdeskv6, with Application Pool Helpdeskv6 set to .NET 4 integrated using ApplicationPoolIndentity. We are currently working on a 2008 R2 domain, no windows firewall etc.
So i have now created a A Record that gives it a nice little name for our intranet users, the A record is called helpdesk (FQDN: helpdesk.my.domain). The IIS site is setup with bindings on standard port 80 for both helpdesk and the FQDN. but yet when i try and browse to the A record address it constantly prompts me for username and password. When i enter my details they work but i dont want users to be prompted.
i have ASP.NET Impersonation and Windows Authentiation enabled - Providers are NTLM and Negotiate. ASP Impersonation is Auth User. NTLM Authentication is ticked in my ASP Project Web Property page.
i have tried just enabling and disabling so many different settings, i have used setsnp -S HTTP/helpdesk.my.domain webserver001 and i have used setsmp -S HTTP/helpdesk webserver001 as i have read alot that apparently needs these in but nothing seems to work.
i have never used ASP Auth with a A Record before so i am at a severe loss please help, hope i supplied enough information as i do not want to have users entere their windows authentication constantly it should be auto so i am just fearfull i am missing a trick here as when i browse via netbios name it works but this is not appropriate for our environment
Forgot to close this out,
The issue was becuase the site wasnt being registered as a Intranet site and Auth details where not being transported over.
Short version:
For IIS 7.5 web applications with Windows Authentication does the end
user need to have Read file access?
Long version:
I have an intranet ASP.NET web app that uses windows authentication. It's installed at dozens of different companies and normally the authentication works fine: users navigate to the site e.g. http://appserver/MyApp, the app recognizes who they're logged in as and displays pages accordingly. I just installed it at a new client and encountered a problem:
When connecting e.g. to http://appserver/MyApp I'm prompted for windows credentials but after entering them I'm repeatedly prompted. After several re-entering credentials I'm shown a 401 error page saying "401 - Unauthorized: Access is denied due to invalid credentials.". So not only is it not passing through my identity but even when entering the username & password it's still denying access.
Giving Read & Execute permissions to the end users of the app solves this problem, but I don't think this should be necessary at all.
In the windows Application Event Log there's a message "File authorization failed for the request" along with Thread account name: NT AUTHORITY\NETWORK SERVICE and User: [the correct workstation users's domain account]. This suggests that the file access is being performed with the User's identity, not the AppPool identity of Network Service. Sure enough if I grant the end user Read & Execute permission (I didn't try Read only) to the application's directory then everything works correctly: when the user browses to the site they're authenticated automatically, not prompted, and the web site correctly recognizes their identity! Therefore my workaround solution is to give Read & Execute permission to Everybody on the application directory...but this is not an ideal solution.
This seems very strange. I've never needed to do this before in IIS 7.5, so far as I recall, and definitely never needed to in IIS 6 or IIS 7. Is this a new IIS7.5 thing? The documentation says that Impersonation is turned off by default. I added a element to the web.config to be sure, removed file permissions other than Network Service, but the problem remained.
Any thoughts? Is it normal for Windows Authenticated sites on IIS 7.5 for end users to need file permissions on the web server files?
Some relevant details:
Network Service
has Full Control file permissions to the app folder.
When connecting from the server itself I was prompted for credentials
but after entering them i'm authenticated and the application works
correctly including displaying my windows login and connecting and
retrieving data from the db. I later determined that it was prompting
for credentials because http://localhost was in the trusted sites
and therefore not recognised as the Intranet Zone and thus not
passing identity through. I also determined that it was working as
this user identity because it's an admin user who has file
permissions.
The web server is running Windows Server 2008 R2 / IIS
7.5. It didn't have IIS on it until I installed it. I installed the default features as well as Windows Authentication, ASP.NET, and
possibly a couple of other items. A separate WCF app I installed that
uses IIS, anonymous authentication & .net 2.0 is working fine on
that web server.
The app install process is a manual copy of files,
creation of IIS App Pools & web apps, updating connection strings,
etc.
I checked the IE security settings. It was recognizing the
server as in the Intranet zone and had the option 'Automatic logon
only in Intranet zone' selected. Also on Advanced Settings the
'Enable Integrated Windows Authentication' option was checked.
After
installing IIS I ran aspnet_regiis -i for .net 2.0 and
aspnet_regiis -iru for .net 4.0.
Anonymous authentication is
disabled for my app and Windows Authentication enabled.
The app is
running on ASP.NET v4 but there's another app I installed
experiencing the same issue running ASP.NET v2.
The app is running
with Identity = Network Service and in 32-bit mode.
Database
connection string includes Trusted Connection=True and database
permissions are granted to the web server account [domain]\[server]$
e.g. DGM\MyServer$.
In IIS > Authentication > Windows Authentication > Providers the list was Negotiate first then NTLM. I tried reordering so NTLM is first.
In the Windows Security Event Log there
were a series of Microsoft Windows security auditing events: Logon
and Logoff. They indicated that the Logon was successful and was
displaying the User Id of the workstation user. This are from when
I'm connecting from another workstation and receive a 401
Unauthorized after several attempts.
I see someone has had this problem reported here but with no solution. Originally I posted in the ASP and then the IIS forums with no answers so far.
Update:
This msdn article says
When Windows authentication is enabled but impersonation is disabled, ASP.NET performs file access checks in the file authorization module using the credentials that are sent from the browser (my emphasis). Impersonation does not need to be enabled, because the FileAuthorizationModule module ensures that the requesting user is allowed read access or write access to the resource, depending on the request verb (for example, GET or POST) before executing the request. This behavior applies to any requests that enter managed code. In earlier versions of ASP.NET, accessing files based on URIs such as "Default.aspx" triggered the access check. In ASP.NET MVC applications, where access to resources is typically performed using extensionless URLs, this check typically does not apply, because there is not a physical file to check. In that case, the FileAuthorizationModule class falls back to checking access-control lists (ACLs) for the folder.
This does suggest that the end user needs permissions to the files (in the case of .aspx) or the folder (for MVC) ... although still this seems slightly tucked away and non-definitive. This article about App Pools says they're used as the identity for securing resources, which contradicts the idea of needing to grant privileges to end users. Unless the rules are different for App Pools and NETWORK SERVICE, which could be the case but would be surprising.
Are authenticated users allowed to the app folder?
We were also fighting with this issue, and started setting up security groups so we could give our users file level permissions. Then one of our server admins stumbled across a couple of new properties that allow the app to authenticate to the file system under set credentials, and resolved the need for the users to have access. Here is what he came up with…
There are two IIS settings that control this:
Physical Path Credentials Physical Path Credentials Logon type
By default, Physical Path Credentials is set to Application User
(Pass-through authentication). This means that IIS doesn’t do any
impersonation when handling Windows Authentication requests. This can,
however, be set to a specific user (though not, unfortunately, the
application pool identity, which would be ideal). Physical Path
Credentials Logon Type is set by default to Clear-Text. For my testing
I set this to Interactive (though this may not be the correct value).
Possible values are Clear-Text, Batch, Interactive, and Network.
To set this up I did the following:
Created a local account (IIS-AccessUser)
Granted IIS-AccessUser read and execute access to the /home directory of the site.
Added IIS-AccessUser to IIS_IUSRS group (necessary for accessing .NET temporary files)
Set IIS-AccessUser as the Physical Path Credentials
Set Physical Path Credentials Logon Type to Interactive
Doing the above allowed me to log in to the application directly,
without having to allow Authenticated Users, or me having to be a
member of any of the groups in the /home folder. It also still
preserved .NET Authorization roles, so I still could not access parts
of the site that I was not allowed to.
The short answer is NO. You are not required to grant file access permissions when using Windows Authentication in IIS 7.0 and IIS 7.5.
We were only able to discover this because our server admin smelled the security and management issues that arise from taking the route of granting file level access to users and groups.
For anyone dealing with this issue or if you are setting up a new IIS7/IIS7.5 server and/or moving from IIS 6, here is an article that gives you all of the Windows Authentication options and configurations that need to be modified to avoid granting file level access to individuals or groups.
Please read the two comments in at the end of the POST for some valid critiques of the methods used in this article.
http://weblogs.asp.net/owscott/iis-using-windows-authentication-with-minimal-permissions-granted-to-disk
In addition to the information in the article, please be aware that IIS 7.5 is not using the web configuration tags for system.web (at least not in my MVC 4 application).
It is looking in the system.webserver tags for authorization configuration (where you will need to list the windows domain\groups a user needs to be in to access your application).
-- DSB
I created an ASP.NET application for an internal purpose, where the domain user accesses a simple web form, fills in the form and submits. The application impersonates the user and sends an email as the logged on domain user to our ticketing system where a ticket is generated from the user who filled out the form. Now, everything works when I test by logging onto the same server that IIS (7.5) is located and submit the form, but when I try to do the same from my desktop (opening browser and pointing to web server), it does not work. After investigating the issue, I discovered that this is likely a double-hop issue (which I confirmed when the exchange admin checked logs after a few failed attempts and found that site was trying to send email as NTAuthority/Anonymous.)
I've combed the web and found a lot of info on this issue, but all I can seem find are articles detailing the issue in relation to earlier versions of IIS (IIS 5 or 6.) I’m using 7.5 so I’m not certain of how the process for resolving this would differ. Could someone who has had this issue on IIS 7.5 post the basic step by step instructions for resolving double-hop as it relates to IIS 7.5 and sending impersonated email to an Exchange server? Something to the effect of, step one – do this, step 2 – do this, etc…
Another question that I have is the following: Many articles that I have read specify setting up a service account for delegation, and then create SPNs...However with IIS 7.5, I have the option of using application pool identities. Would application pool identities work with delegating impersonation, or would a service account be required to fix the issue?
Thanks all!
From your description, it sounds like your ASP.NET application is trying to determine the logged in user by their Windows network login credentials?
If so, all you should need to do is turn off "Enable Anonymous Access" in your IIS site and make sure that "Authenticated Access" has the "Integrated Windows Authentication" turned on. Then IIS should properly query the browser for their login info and the session should use the user's credentials. This assumes a few things about the client browser used and if something other than Internet Explorer is used, then you might also need to turn on one of the other authentication methods so that the other browsers will properly prompt the user for their network login credentials. Sorry I don't have a running IIS 7.5 server at the moment to give you the exact site properties and descriptions to look at. So if you cannot determine it from my description here, hopefully someone else might add on with that or I can try to follow up later if you need.
I have a website in IIS 6.0 using an application pool with a custom service account. When I browse the website, I get an error "service unavailable" and the error in event log says
The identity of application pool 'SampleAppPool' is invalid, so the World Wide Web Publishing Service can not create a worker process to serve the application pool. Therefore, the application pool has been disabled.
I think the utility "Aspnet_regiis" can be used to grant access to an account to IIS metabase according to this article, but is that the right way to fix this issue? Because this utility is used for multiple things and may do more than just granting the permissions to the account, or should I just add the account manually to IIS_WPG group?
When I see this in IIS 6 and the user has a custom app pool identity, the problem typically originates in the entry of credentials in the app pool properties. So there are generally two origins for the issue.
One is a simple typo in the credentials, unfortunately the form validation is not very good in IIS 6, so I often will have users change the identity of the app pool, then immediately check that the credentials "took" and/or check the System event log for W3SVC and related errors.
The second specific cause I see in this scenario is when people enter an Active Directory user, they sometimes forget to add the domain name. (e.g. DOMAIN\Username). Which leads me to the next point, the IIS_WPG is the builtin local group which grants members the required ACLs to run as an app pool identity. The aspnet_regiis.exe -ga grants the same thing to users, but IMO it is best suited for use when the IIS_WPG group is not an option. Also a dedicated app pool user account is generally a good idea. If the AD user password is changed, you'll bring your app to its knees until you again re-enter the credentials in the IIS Manager.
Edit: I added some para breaks to make this chunk more readable.
I had this same problem and I resolved it by starting the application pool. Ours was stopped even though IIS was running.
"The identity of application pool 'SampleAppPool' is invalid..."
Every time I have had that error, it was because the user name and password where not correctly entered in the application pool. This happens also when you import the pool settings from another server. Reentering the password in the application pool identity configuration has always solved the problem.
Once you get that right, you will probably meet the second problem you are describing, but that's an unrelated issue. It can be fixed as you describe, or even manually granting the required access permissions to the application pool identity.
If you are connecting to a remote machine using one or more remote access tools, take note: your keyboard mappings may be getting screwed up somewhere along the way!
In my case, I tried typing out certain letters of the password in a plain text editor on the remote machine (not necessarily in the same order, to retain security). When attempting to type the dollar character, I found that if I used the left shift key I got a "$" but if I used the right shift key I got a "4".
Once I had that figured out, I could enter the correct password for the Application Pool Identity. (Note: when filling out the identity section, IIS does not validate the password you enter against the user identity, only that the two passwords you enter match each other).