M-129: Microsoft FrontPage SmartHTML Interpreter Vulnerability

   
[***** Start Microsoft Security Bulletin MS02-053 *****]

Originally posted: September 25, 2002

Summary

Who should read this bulletin: Web site administrators using Microsoft® 
FrontPage Server Extensions 

Impact of vulnerability: Buffer overrun or denial of service 

Maximum Severity Rating: Critical 

Recommendation: Web site administrators should apply the patch or ensure 
that the SmartHTML Interpreter is not available on the server. 

Affected Software: 

Microsoft FrontPage Server Extensions 2000 
Microsoft FrontPage Server Extensions 2002 
Microsoft Windows 2000 (shipped FPSE 2000) 
Microsoft Windows XP (shipped FPSE 2000) 

Technical details

Technical description: 

The SmartHTML Interpreter (shtml.dll) is part of the FrontPage Server 
Extensions (FPSE), and provides support for web forms and other 
FrontPage-based dynamic content. The interpreter contains a flaw that 
could be exposed when processing a request for a particular type of 
web file, if the request had certain specific characteristics. This 
flaw affects the two versions of FrontPage Server Extensions differently. 
On FrontPage Server Extensions 2000, such a request would cause the 
interpreter to consume most or all CPU availability until the web service 
was restarted. An attacker could use this vulnerability to conduct a 
denial of service attack against an affected web server. On FrontPage 
Server Extensions 2002, the same type of request could cause a buffer 
overrun, potentially allowing an attacker to run code of his choice. 

Mitigating factors: 

The IIS Lockdown Tool, if used to configure a static web server, disables 
the SmartHTML Interpreter. Servers on which this has been done could not 
be affected by the vulnerability. 

FrontPage Server Extensions install on IIS 4.0, 5.0 and 5.1 by default, 
but can be uninstalled if desired. Servers on which this has been done 
could not be affected by the vulnerability. 

Severity Rating:  Internet Servers Intranet Servers Client Systems 
FrontPage Server      Critical         Moderate          None 
Extensions 2000       
FrontPage Server      Critical         Moderate          None
Extensions 2002 
 
The above assessment is based on the types of systems affected by the 
vulnerability, their typical deployment patterns, and the effect that 
exploiting the vulnerability would have on them. 

Vulnerability identifier: CAN-2002-0692 

Tested Versions:
Microsoft tested FrontPage Server Extensions 2000 and 2002 to assess 
whether they are affected by these vulnerabilities. Previous versions 
are no longer supported, and may or may not be affected by these 
vulnerabilities.


Patch availability
Download locations for this patch: 

Microsoft FrontPage Server Extensions 2002 for all platforms 
http://download.microsoft.com/download/FrontPage2002/fpse1002/1/W98NT42KMeXP/EN-US/fpse1002.exe

Microsoft FrontPage Server Extension 2000 for NT4 
http://download.microsoft.com/download/fp2000fd2000/Patch/1/W9XNT4Me/EN-US/fpse0901.exe 

Microsoft FrontPage Server Extensions 2000 for Windows XP 
- http://www.microsoft.com/downloads/release.asp?ReleaseID=42995 
- Windows Update
  http://windowsupdate.microsoft.com/R1092/v31site/x86/w98/en/thanksstart.htm

Microsoft FrontPage Server Extensions 2000 for Windows 2000 
- http://www.microsoft.com/downloads/release.asp?ReleaseID=42954 
- Windows Update
  http://windowsupdate.microsoft.com/R1092/v31site/x86/w98/en/thanksstart.htm 

Additional information about this patch

Installation platforms: 

This patch can be installed on: 
FrontPage Server Extensions 2002: The patch can be applied on all platforms 
which support FrontPage Server Extensions 2002. 

FrontPage Server Extensions 2000: The patches can be applied on the following 
systems running FrontPage Server Extensions 2000 - Windows XP, Windows 2000, 
and NT4. 

Inclusion in future service packs:
The fix for this issue will be included in Windows 2000 SP4, Windows XP SP2 
and any future service packs for FPSE 2002. 

Reboot needed: Yes 

Patch can be uninstalled:

FrontPage Server Extensions 2000 patches on Windows 2000 and Windows XP can 
be uninstalled. 

FrontPage Server Extensions 2000 patches for NT4 cannot be uninstalled. 

FrontPage Server Extensions 2002 patches cannot be uninstalled. 

Superseded patches: None. 

Verifying patch installation: 

Users who are applying the patch on Windows 2000 or Windows XP should refer 
to Q324096 

Users who are applying the patch for FrontPage Server Extensions 2000 please 
refer to Knoweldege Base article Q329085 

Users who are applying the patch for FrontPage Server Extensions 2002 please 
refer to Knoweldege Base article Q329086 

Caveats:
Users running FrontPage Server Extensions 2002 on any supported platform who 
have not applied the latest update will need to apply the update before 
installing this patch. To learn more about the update, please read Q317296. 
To go directly to the FrontPage Server Extensions 2002 Update, click here. 

Localization:
Localized versions of this patch are available at the locations discussed in 
"Patch Availability". 

Obtaining other security patches: 
Patches for other security issues are available from the following locations: 

Security patches are available from the Microsoft Download Center, and can be 
most easily found by doing a keyword search for "security_patch". 

Patches for consumer platforms are available from the WindowsUpdate web site.
 
Other information: 
Acknowledgments
Microsoft thanks  Maninder Bharadwaj of Digital Defense Services part of 
Digital GlobalSoft Ltd. for reporting this issue to us and working with us 
to protect customers. 

Support: 

Microsoft Knowledge Base article Q324096 discusses this issue and will be 
available approximately 24 hours after the release of this bulletin. Knowledge 
Base articles can be found on the Microsoft Online Support web site. 

Technical support is available from Microsoft Product Support Services. There 
is no charge for support calls associated with security patches. 

Security Resources: The Microsoft TechNet Security Web Site provides additional 
information about security in Microsoft products. 

Disclaimer: 
The information provided in the Microsoft Knowledge Base is provided "as is" 
without warranty of any kind. Microsoft disclaims all warranties, either 
express or implied, including the warranties of merchantability and fitness 
for a particular purpose. In no event shall Microsoft Corporation or its 
suppliers be liable for any damages whatsoever including direct, indirect, 
incidental, consequential, loss of business profits or special damages, 
even if Microsoft Corporation or its suppliers have been advised of the 
possibility of such damages. Some states do not allow the exclusion or 
limitation of liability for consequential or incidental damages so the 
foregoing limitation may not apply. 

Revisions: 

V1.0 (September 25, 2002): Bulletin Created. 
V1.1 (September 26, 2002): Bulletin updated to add URL's for Windows XP and 
Windows 2000 patches on the Microsoft Download Center

[***** End Microsoft Security Bulletin MS02-053 *****]

    Voice:          +1 925-422-8193 (7 x 24)
    FAX:            +1 925-423-8002
    STU-III:        +1 925-423-2604
    E-mail:          ciac@ciac.org
    World Wide Web:  http://www.ciac.org/
    Anonymous FTP:   ftp.ciac.org