Microsoft has warned Windows NT and 2000 users of a newly discovered flaw in its software that could allow attacks to take complete control of their systems.
The warning came as the company posted a patch on its website that it said fixes the flaw.
The problem, according to Microsoft, comes from a flaw in the security around its debugger tools, which lets any user run any program on the system, with the highest privileges.
The debugging tool enables programs to perform diagnostic and analytic functions on applications as they are running on the operating system.
One of these capabilities allows the program to connect to any running program and take control of it. The program can then issue commands to the controlled program, including the launching of other programs.
Having gained access to that capability, an attacker could stop, run or erase any applications or part of the operating system.
However, Microsoft said that the potential for the flaw to be exploited was limited because it would require the attacker to have gained access to the computer in the first place and have privileges to execute code.
The company maintained that this should reduce the danger, as best practices should prevent such access.
Nevertheless, the vulnerability has been given a "critical" rating for client systems.
"The vulnerability does not affect Windows XP and the patch fully eliminates the vulnerability," said a Microsoft spokesman.
The patch, as well as details of the flaw, have been posted on Microsoft's website.
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