Original URL: http://www.theregister.co.uk/2005/07/18/winxp_dos_bug/

MS probes Win XP SP2 kernel bug

Crash risk dummy

By John Leyden

Posted in Security, 18th July 2005 14:59 GMT

Windows XP SP2 has proved to be a lot more robust than critics give Microsoft credit for but that doesn't mean it's immune from security problems. Security researcher Tom Ferris of Security-Protocols.com discovered a bug in XP's kernel that might be used by hackers to crash even fully patched systems with Windows firewall switched on.

The vulnerability stems from a flaw in Remote Desktop Services (disabled by default except on Windows XP Media Center Edition). A maliciously constructed RDP (Remote Desktop Protocol) request might be used to mount denial of service attacks but Ferris said the bug doesn't lend itself to injecting hostile code into vulnerable systems. Microsoft has confirmed the vulnerability but says the risk is limited to denial of service attacks. "We have not been made aware of attacks that try to use the reported vulnerability or of customer impact at this time, but we are aggressively investigating the public reports," it added.

Nonetheless security alert notification firm Secunia rates the bug as "critical". Seperately, Secunia last week also posted info on another Windows XP SP2 security bug. It warns that a flaw in a Windows Network Connections Service component (netman.dll) also poses a denial of service risk but this is only applies to local users not remote attackers hence a much reduced security risk. ®

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