Article ID: 295534
Article Last Modified on 11/21/2006
APPLIES TO
- Microsoft Internet Information Services 5.0
- Microsoft Internet Information Server 4.0
This article was previously published under Q295534
SYMPTOMS
A vulnerability exists in Microsoft Internet Information Services (IIS) 5.0 and Microsoft Internet Information Server (IIS) 4.0 that can enable a malicious user to run (execute) operating system commands on an affected Web server. This gives the malicious user the ability to modify Web pages, add, change, or delete files, reformat the hard disk, or take other actions (such as uploading any code to the server and running it).
Best practices, if followed, can make it difficult or impossible for an attacker to exploit the vulnerability. Even if an attacker successfully exploits it, the vulnerability does not grant the attacker administrative control over the server. Instead, the vulnerability grants the attacker privileges that are normally reserved for a user who can log on to the server interactively. Nevertheless, even these privileges can enable a malicious user to cause widespread damage and allow a point from which the malicious user can launch additional attacks in the hope of gaining additional privileges.
Mitigating Factors:
- This vulnerability does not provide a way for the attacker to learn the folder structure on the server. As a result, if the operating system is installed on a separate drive from the Web root or in non-standard folders, it can prevent an attacker from locating programs of interest.
- This vulnerability does not provide administrative access to the server. If you followed the recommendations in the IIS 4.0 and IIS 5.0 security checklists, sensitive programs are moved to folders that only the administrator can access, and non-administrative access to server resources is severely restricted.
CAUSE
This vulnerability occurs because of an error in the functionality that processes requests to run programs that are housed on the server. A superfluous decoding operation could give an attacker the opportunity to bypass security checks and escape the server's virtual folder structure, thereby enabling the attacker to run operating system commands on the server.
RESOLUTION
For additional information on what is fixed by the following patches, click the article number below to view the article in the Microsoft Knowledge Base:
297860 IIS 5.0 Security and Post-Windows NT 4.0 SP5 IIS 4.0 Patch Rollup
Internet Information Services 5.0
To resolve this problem, either obtain the hotfix referenced in this section or Windows 2000 Security Rollup Package 1 (SRP1). For additional information about SRP1, click the article number below to view the article in the Microsoft Knowledge Base:
311401 Windows 2000 Security Rollup Package 1 (SRP1), January 2002
To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
260910 How to Obtain the Latest Windows 2000 Service Pack
The following file is available for download from the Microsoft Download Center:
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file. The English version of this fix should have the following file attributes or later:
Date Time Version Size File name
--------------------------------------------------------
05/04/2001 11:48a 5.0.2195.3407 245,520 Adsiis.dll
05/04/2001 11:48a 5.0.2195.3407 332,560 Asp.dll
08/26/2000 06:30p 6,512 Fixerr.js
11/10/2000 11:21p 5.0.2195.3407 593,976 Fp4autl.dll
03/27/2001 10:10p 5.0.2195.3407 445,712 Httpext.dll
05/04/2001 11:48a 5.0.2195.3407 56,592 Httpodbc.dll
05/04/2001 11:48a 5.0.2195.3407 122,640 Iisrtl.dll
05/04/2001 11:48a 5.0.2195.3407 13,584 Infoadmn.dll
05/04/2001 11:48a 5.0.2195.3407 245,520 Infocomm.dll
05/04/2001 11:48a 5.0.2195.3407 62,736 Isatq.dll
05/04/2001 11:48a 5.0.2195.3407 46,352 Ism.dll
05/04/2001 11:48a 5.0.2195.3407 76,560 Msw3prt.dll
10/17/2000 01:38p 5.0.2195.3407 6,928 Schmupd.exe
05/04/2001 11:48a 5.0.2195.3407 41,232 Ssinc.dll
05/04/2001 11:48a 5.0.2195.3407 7,440 W3ctrs.dll
05/04/2001 11:48a 5.0.2195.3407 357,648 W3svc.dll
NOTE: You can install this patch on systems that are running Microsoft Windows 2000 Gold, Windows 2000 Service Pack 1, or Windows 2000 Service Pack 2.
Internet Information Server 4.0
To resolve this problem, obtain the Windows NT 4.0 Security Rollup Package. For additional information, 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)
A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that you determine are at risk of attack. Evaluate the computer's physical accessibility, network and Internet connectivity, and other factors to determine the degree of risk to the computer. See the associated Microsoft Security Bulletin to help determine the degree of risk. This hotfix may receive additional testing. If the computer is sufficiently at risk, we recommend that you apply this hotfix now.
To resolve this problem immediately, download the hotfix by following the instructions later in this article or contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:
Note In special cases, charges that are ordinarily incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The following file is available for download from the Microsoft Download Center:
![[GRAPHIC: Download]](/wiki/index.php?title=File:Download.gif){kind=small}
Download Q295534i.exe now
NOTE: Q295534is.exe are the Symbols files.
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file. The English version of this fix should have the following file attributes or later:
Date Time Version Size File name Platform
------------------------------------------------------------------
04/11/2001 01:32p 4.2.764.1 214,544 Adsiis.dll x86
04/11/2001 01:33p 4.2.764.1 330,672 Asp.dll x86
04/02/2001 04:55p 4.0.2.4701 593,976 Fp4autl.dll x86
04/11/2001 01:32p 4.2.764.1 81,888 Ftpsvc2.dll x86
04/11/2001 01:32p 4.2.764.1 55,392 Httpodbc.dll x86
04/11/2001 01:32p 4.2.764.1 98,912 Iischema.dll x86
04/11/2001 01:31p 4.2.764.1 63,472 Iislog.dll x86
04/11/2001 01:31p 4.2.764.1 185,792 Infocomm.dll x86
04/11/2001 01:31p 4.2.764.1 29,520 Iscomlog.dll x86
04/11/2001 01:35p 4.2.764.1 54,560 Ism.dll x86
04/02/2001 04:55p 4.0.1381.7086 375,056 Kernel32.dll x86
04/11/2001 01:36p 4.2.764.1 9,680 Schmupd.exe x86
04/11/2001 01:32p 4.2.764.1 38,256 Ssinc.dll x86
04/11/2001 01:32p 4.2.764.1 25,360 Sspifilt.dll x86
04/11/2001 01:32p 4.2.764.1 229,024 W3svc.dll x86
04/11/2001 01:31p 4.2.764.1 88,032 Wam.dll x86
08/20/1999 12:26a 4.0.1381.321 171,280 W3svc.dll Alpha
NOTE: You can install this patch on systems that are running Microsoft Windows NT 4.0 Service Pack 5 or Windows NT 4.0 Service Pack 6a.
Windows NT Server version 4.0, Terminal Server Edition
To resolve this problem, obtain the Windows NT Server 4.0, Terminal Server Edition, Security Rollup Package (SRP). For additional information about the SRP, click the article number below to view the article in the Microsoft Knowledge Base:
317636 Windows NT Server 4.0, Terminal Server Edition, Security Rollup Package
STATUS
Internet Information Services 5.0
Microsoft has confirmed that this problem may cause a degree of security vulnerability in Internet Information Services 5.0. This problem was first corrected in Windows 2000 Service Pack 3.
Internet Information Server 4.0
Microsoft has confirmed that this problem may cause a degree of security vulnerability in Internet Information Server 4.0.
MORE INFORMATION
For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base:
265173 The Datacenter Program and Windows 2000 Datacenter Server Product
For additional information about how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base:
296861 Use QChain.exe to Install Multiple Hotfixes with One Reboot
For more information on this vulnerability, see the following Microsoft Web site:
Additional query words: kbIISCom security_patch kbWin2000srp1
Keywords: kbbug kbfix kbwin2000presp3fix kbgraphxlinkcritical kbsecvulnerability kbqfe kbwin2000sp3fix kbsecurity kbsechack kbhotfixserver KB295534
