When an administrator in Windows NT or Windows 2000 changes a user policy, the policy is not properly updated if the local ntconfig.pol is not writable by the user, which could allow local users to bypass restrictions that would otherwise be enforced by the policy, possibly by changing the policy file to be read-only.
When the Ntconfig.pol file is used on a server whose name is longer than 13 characters, Windows NT does not properly enforce policies for global groups, which could allow users to bypass restrictions that were intended by those policies.
Windows NT 4.0 allows local users to cause a denial of service via a user mode application that closes a handle that was opened in kernel mode, which causes a crash when the kernel attempts to close the handle.
Win32k.sys in Windows NT 4.0 before SP2 allows local users to cause a denial of service (crash) by calling certain WIN32K functions with incorrect parameters.
Windows NT 3.51 and 4.0 allow local users to cause a denial of service (crash) by running a program that creates a large number of locks on a file, which exhausts the NonPagedPool.
Windows NT 4.0 allows local users to cause a denial of service (crash) via an illegal kernel mode address to the functions (1) GetThreadContext or (2) SetThreadContext.
GINA in Windows NT 4.0 allows attackers with physical access to display a portion of the clipboard of the user who has locked the workstation by pasting (CTRL-V) the contents into the username prompt.
RSH service utility RSHSVC in Windows NT 3.5 through 4.0 does not properly restrict access as specified in the .Rhosts file when a user comes from an authorized host, which could allow unauthorized users to access the service by logging in from an authorized host.
Windows NT Local Security Authority (LSA) allows remote attackers to cause a denial of service via malformed arguments to the LsaLookupSids function which looks up the SID, aka "Malformed Security Identifier Request."