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  3. Microsoft IIS 5.0 WebDAV Authentication Bypass Vulnerability

Microsoft IIS 5.0 WebDAV Authentication Bypass Vulnerability

Risk

Medium

Date Discovered

June 9, 2009

Description

Microsoft Internet Information Services (IIS) is prone to an authentication-bypass vulnerability because it fails to properly enforce access restrictions on certain requests to a site that requires authentication. An attacker can exploit this issue to gain unauthorized access to protected resources, which may lead to other attacks. This issue affects IIS 5.0.

Technologies Affected

  • Avaya Messaging Application Server
  • Avaya Messaging Application Server MM 1.1
  • Avaya Messaging Application Server MM 2.0
  • Avaya Messaging Application Server MM 3.0
  • Avaya Messaging Application Server MM 3.1
  • Microsoft IIS 5.0

Recommendations

Block external access at the network boundary, unless external parties require service.

If global access isn't needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of successful exploits.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.

Deploy NIDS to detect and block attacks and anomalous activity such as requests containing suspicious URI sequences. Since the webserver may log such requests, review its logs regularly.

Run all software as a nonprivileged user with minimal access rights.

To limit the consequences of successful exploits, run server processes within a restricted environment using facilities such as chroot or jail.
Microsoft has released an advisory and fixes for this issue. Please see the references for details.

Credits

Yamata Li
Copyright © Symantec Corporation.
Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Security Response. Reprinting the whole or part of this alert in any medium other than electronically requires permission from secure@symantec.com.

Disclaimer
The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.
Symantec, Symantec products, Symantec Security Response, and secure@symantec.com are registered trademarks of Symantec Corp. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners.

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