Date: Wed, 9 Jun 1999 01:07:04 +0200 From: mRm3n4c3 To: BUGTRAQ@netspace.org Subject: Bug in WTS 4.0 on WinNT 4.0 sp4 I have recently encountered what i believe to be a bug in NT security when using Windows Terminal Server 4.0 on NT 4.00.1381 (Service Pack 4). The problem occured in an environment with 2 WTS servers using Metaframe and running a Loadbalancing service, two file/ print servers also running Oracle databases and one name server set to be PDC. The users homedirectories containing WTS/ NT profiles are located on the PDC. If you log on to the WTS and type the wrong password more than three times, the your account gets locked out. BUT, if you choose to continu trying anyway, and after some time manage to type in the correct password, the WTS will let you log on as an 'anonymous user' account, using either a locally stored profile or a default profile. This beacause the PDC denies access to the homedir. The funny thing is, you have no access to the PDC, which only replies with 'your account is locked out', but the WTS ignores this and lets you browse the network, map up locally shared drives/ catalogues, run command.com / cmd.exe or regedit/ regedt32. I have not found out what kind of access th user hasat this point, but more than he/ she should anyways... Now, the user in this example was set up like this in usermgr: Homedir path \\nt40pdc\usernameshare$ No terminal homedir Allow logon, no timeouts. This means two severe problems: If the users profile is unavailable for some reason, the user is logged on anyway. The 'account locked out' function does not work on WTS Well, this should be something to work on, happy hunting! (][mistr][) (][there is no spoon][) ------------------------------------------------------------------------------- Date: Thu, 10 Jun 1999 16:58:39 +0200 From: mRm3n4c3 To: BUGTRAQ@netspace.org Subject: Re: Bug in WTS 4.0 on WinNT 4.0 sp4 I'm sorry to see I have neglected to inform you of this. There is another NT file/ print server running also exchange 5.0... It is this server that is set to be BDC. Again, sorry for not telling you all this right away. (][mistr][) (][there is no spoon][) *********** REPLY SEPARATOR *********** On 10.06.99 at 16:13 Aaron Power wrote: > >Are your WTS machines configured as BDC's or member servers? > >Aaron Power. .·°\|/°`'´°·.:[(mistr@marmelade.net)]:.·°`'´°\|/°·. ------------------------------------------------------------------------------- Date: Thu, 10 Jun 1999 16:13:32 +1000 From: Aaron Power To: BUGTRAQ@netspace.org Subject: Re: Bug in WTS 4.0 on WinNT 4.0 sp4 I tried this on our test site consisting of a single WTS running Metaframe (no load balancing obviously) and a single BDC and could NOT replicate the fault as described. Are your WTS machines configured as BDC's or member servers? Aaron Power. ------------------------------------------------------------------------------- Date: Fri, 11 Jun 1999 12:57:48 -0700 From: Bill Stout To: BUGTRAQ@netspace.org Subject: Re: Bug in WTS 4.0 on WinNT 4.0 sp4 -----Original Message----- >From: mRm3n4c3 [mailto:mistr@MARMELADE.NET] >If you log on to the WTS and type the wrong password more than three times, the your account gets locked out. BUT, if you choose to continu trying anyway, and after some time manage to type in the correct password, the WTS will let you log on as an 'anonymous user' account, using either a locally stored profile or a default profile. It appears to be working like it should. The 'Anonymous User' accounts are local guest accounts on the Citrix server. If you logon using only username/password, the correct behaviour is for NT to scan the local users for the username, then the domain. A failed logon using username/password only would traditionally use the 'guest' account. Extract from http://support.microsoft.com/support/kb/articles/q103/3/90.asp: "If the Domain specified in the SMB is NULL [None specified] then The Advanced Server will treat this a local network logon. It will check for a matching account in its own SAM Database. If it finds a matching account then The SMB password is compared to the SAM Database password. If the password matches then The Command Completed Successfully. If the password does NOT match then The User is prompted for a password. It is retested as above. System error 1326 has occurred. Logon failure: unknown user name or bad password. End If it does NOT find the account in the local SAM Database then The Advanced Server will Simultaneously ask another Advanced Server in each Domain that it Trusts if it has account that matches the SMB account. If no Trusted Domains respond to request to identify the account then Guest permissions are tested on the Original Advanced Server - not the Trusted server. If the Guest account is Enabled The Command Completed Successfully. If the Guest account is Disabled System error 1326 has occurred. Logon failure: unknown user name or bad password. End " Bill Stout