From pgrundl@kpmg.dk Thu Apr 18 02:54:41 2002 From: "[iso-8859-1] Peter Gründl" To: bugtraq Date: Wed, 17 Apr 2002 11:28:11 +0200 Subject: KPMG-2002011: Windows 2000 microsoft-ds Denial of Service [The following text is in the "iso-8859-1" character set] [Your display is set for the "US-ASCII" character set] [Some characters may be displayed incorrectly] -------------------------------------------------------------------- -=>Windows 2000 microsoft-ds Denial of Service<=- courtesy of KPMG Denmark BUG-ID: 2002011 Released: 17th Apr 2002 -------------------------------------------------------------------- Problem: ======== The default LANMAN registry settings on Windows 2000 could allow a malicious user, with access to TCP port 445 on your Windows 2000, to cause a Denial of Service. Vulnerable: =========== - Windows 2000 Server (SP0, SP1, SP2) - Windows 2000 Advanced Server (SP0, SP1, SP2) - Windows 2000 Professional (SP0, SP1, SP2) Details: ======== Sending malformed packets to the microsoft-ds port (TCP 445) can result in kernel ressources being allocated by the LANMAN service. The consequences of such an attack could vary from the Windows 2000 host completely ignoring the attack to a blue screen. An attack could be something as simple as sending a continuous stream of 10k null chars to TCP port 445. The most common symptoms would be that the LANMAN service would allocate a lot of kernel memory, until a point, where very few applications would be able to run. The routine that draws windows would commence to draw incomplete windows, the warning "beep" would be replaced by an error stating that the sound driver could not be loaded. Internet Information Server would no longer be able to service .asp pages, attempts to reboot the server (as administrator) would result in the error "You do not have permissions to shutdown or restart this computer.", aso. It would frequently be possible to cause the system service to enter a state where it constantly used 100% CPU usage. A PC was left in this state over the weekend, to see if it would recover on it's own. It did not recover. Vendor URL: =========== You can visit the vendors webpage here: http://www.microsoft.com Vendor response: ================ The vendor was contacted mid-October, 2001. The vendor released a Q-article, describing the problem and possible solutions on the 11th of April, 2002. KPMG was notified of the publication on the 17th of April, 2002. Corrective action: ================== The vendor has suggested two possible solutions, available here: http://support.microsoft.com/default.aspx?scid=kb;en-us;Q320751 Author: Peter Gründl (pgrundl@kpmg.dk) -------------------------------------------------------------------- KPMG is not responsible for the misuse of the information we provide through our security advisories. These advisories are a service to the professional security community. In no event shall KPMG be lia- ble for any consequences whatsoever arising out of or in connection with the use or spread of this information. --------------------------------------------------------------------