MS99-047: Unchecked Print Spooler Buffer May Expose System Vulnerability (243649)


The information in this article applies to:

  • Microsoft Windows NT Server 4.0 Terminal Server Edition
  • Microsoft Windows NT Workstation 4.0
  • Microsoft Windows NT Server 4.0
  • Microsoft Windows NT Server, Enterprise Edition 4.0
  • Microsoft BackOffice Server 4.0
  • Microsoft BackOffice Server 4.5
  • Microsoft BackOffice Small Business Server 4.0
  • Microsoft BackOffice Small Business Server 4.5
This article was previously published under Q243649

SYMPTOMS

When you pass random data to some of the functions in the Windows NT 4.0 print spooler sub-system Application Programming Interface (API) that have unchecked buffers, the print spooler service may stop responding (hang). If the affected API is provided with a specially-malformed argument, it may be possible to bypass the computer security settings and run an unauthorized program using a buffer overrun technique.

The majority of the affected APIs require that the user be a member of the Power Users or Administrators group. However, at least one API is callable by users that have not been assigned extended security permissions. The calls can also be made remotely.

RESOLUTION

Windows NT Server or Workstation 4.0

To resolve this problem, obtain the individual package referenced below or obtain the Windows NT 4.0 Security Rollup Package. For additional information on the SRP, click the article number below to view the article in the Microsoft Knowledge Base:

299444 Post-Windows NT 4.0 Service Pack 6a Security Rollup Package (SRP)

The English-language version of this fix should have the following file attributes or later: 
   Date       Time     Size      File name      Platform
   -------------------------------------------------------------
   11/03/99   01:23p    18,704   Localmon.dll   x86
   11/03/99   01:23p   140,560   Localspl.dll   x86
   11/03/99   01:23p    13,072   Lprhelp.dll    x86
   11/03/99   01:23p    21,776   Lprmon.dll     x86
   11/03/99   06:36p    48,400   Spoolss.dll    x86
   11/03/99   01:23p    39,184   Spoolss.exe    x86
   11/03/99   01:23p    80,144   Win32spl.dll   x86

   11/03/99   01:23p    32,016   Localmon.dll   Alpha
   11/03/99   01:23p   236,304   Localspl.dll   Alpha
   11/03/99   01:23p    22,288   Lprhelp.dll    Alpha
   11/03/99   01:23p    34,064   Lprmon.dll     Alpha
   11/03/99   06:36p    85,264   Spoolss.dll    Alpha
   11/03/99   01:23p    65,808   Spoolss.exe    Alpha
   11/03/99   01:23p   136,464   Win32spl.dll   Alpha
NOTE: Lmmon.dll and Lmmon.dbg were inadvertently packaged in Q243649.exe. These files are not installed when running Q243649.exe and are not required to protect against the vulnerability described in this kb article.

The Intel-based version of this hotfix has been posted to the following Internet location as Q243649.exe:

http://download.microsoft.com/download/winntsrv40/Patch/Spooler-fix/NT4/EN-US/Q243649.exe

The Alpha-based version of this hotfix has been posted to the following Internet location as Q243649.exe:

http://download.microsoft.com/download/winntsrv40/Patch/Spooler-fix/ALPHA/EN-US/Q243649.exe

NOTE: You must be running Service Pack 4 (SP4) or later to apply this fix.

Windows NT Server 4.0, Terminal Server Edition

To resolve this problem, obtain the latest service pack for Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

152734 How to Obtain the Latest Windows NT 4.0 Service Pack


STATUS

Windows NT 4.0

Microsoft has confirmed that this problem may cause a degree of security vulnerability in Windows NT 4.0.

Windows NT Server 4.0, Terminal Server Edition

Microsoft has confirmed that this problem may cause a degree of security vulnerability in Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT Server 4.0, Terminal Server Edition Service Pack 6.

MORE INFORMATION

For related information on this problem, please visit the following Microsoft Web site:

http://www.microsoft.com/technet/security/bulletin/fq99-047.mspx

For additional security-related information about Microsoft products, please visit the following Microsoft Web site:

http://www.microsoft.com/security/

Modification Type:MajorLast Reviewed:8/21/2006
Keywords:kbHotfixServer kbQFE kbdownload kbfix kbprb kbprint kbSecurity KbSECVulnerability KB243649
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