Microsoft confirms Windows NT security flaw

IDG News Service

SAN FRANCISCO - Microsoft Corp. last week acknowledged a security flaw in its Windows NT operating system that could allow a person to access protected files on a workstation or even deny users access to a Windows NT server.

The bug surfaces at an embarrassing time for the software maker. The company is scrambling to address privacy concerns raised last week over a feature in its Windows 98 operating system that allows Microsoft to compile a hardware profile of users when they register their software.

The vulnerability in Windows NT is exploited by running a malicious program when a system is in screensaver mode, a Microsoft product manager confirmed. The program can elevate the user's log-in status to that of an administrator, giving him or her access to protected files in the computer.

Scott Culp, security product manager at Microsoft, said the company planned to have a patch for the flaw available by late last week. Microsoft planned to post the patch on its Web site at www.microsoft.com/security, Culp said.

Federal agencies view the flaw as a potential security threat. But the Navy believes the threat would be minimized as long as users are aware of the problems and make the necessary fixes, said David Mihelcic, head of the network security section of the Naval Research Laboratory, Washington, D.C.

"We understand there are flaws in Windows NT, just as there are flaws in Unix" and any other operating system, Mihelcic said. The Navy has processes in place to make sure users are aware of security problems and download security patches fairly rapidly, he said.

The flaw was discovered by an Indian software firm, Cybermedia Software Private Ltd. It affects all versions of Windows NT, including two beta versions of Windows 2000, formerly known as Windows NT 5.0. The problem will be fixed before Windows 2000 is released commercially, Culp said.

"This vulnerability requires that a person be able to log on to a system locally, that they can actually put their hands on the keyboard," he said. "It's not something you can exploit over the Internet."

Exploiting the vulnerability on a workstation would give a user access to protected files on that machine, Culp explained. Because most workstation users already have administrator status on their own machines, the issue is largely moot, he said.

Culp acknowledged that on a Windows NT server, a hacker could allow a user to become a domain administrator, empowering him or her to read protected files elsewhere on a network and to deny clients access to the server. However, standard security procedures at corporations prevent nonadministrators from logging onto servers, Culp said.

"The primary vulnerabilities are in workstations and terminal servers," he said, adding that the hack takes a lot of skill and would constitute a "sophisticated technical attack."

Microsoft set up an e-mail address where users can report suspected security issues, which is how Cybermedia alerted Microsoft to the Windows NT problem, Culp said. "Microsoft takes security seriously. We know it's important to our customers," he said.

The Windows NT incident follows another security issue in Windows 98. Microsoft recently was forced to admit that a feature in Windows 98 assigns a unique identifier to documents created in Office 97, although the vendor insists the feature does not allow documents to be linked back to users.