Security Advisory

Microsoft Security Advisory 975191

Vulnerabilities in the FTP Service in Internet Information Services

Published: September 01, 2009 | Updated: October 13, 2009

Version: 3.0

General Information

Executive Summary

Microsoft has completed the investigation into a public report of this issue. We have released MS09-053 to address this issue. For more information about this issue, including download links for an available security update, please review MS09-053. The vulnerabilities addressed are the IIS FTP Service DoS Vulnerability (CVE-2009-2521) and the IIS FTP Service RCE and DoS Vulnerability (CVE-2009-3023).

Other Information

Microsoft Active Protections Program (MAPP)

To improve security protections for customers, Microsoft provides vulnerability information to major security software providers in advance of each monthly security update release. Security software providers can then use this vulnerability information to provide updated protections to customers via their security software or devices, such as antivirus, network-based intrusion detection systems, or host-based intrusion prevention systems. To determine whether active protections are available from security software providers, please visit the active protections Web sites provided by program partners, listed in Microsoft Active Protections Program (MAPP) Partners.



  • Customers in the United States and Canada can receive technical support from Security Support. For more information about available support options, see Microsoft Help and Support.
  • International customers can receive support from their local Microsoft subsidiaries. For more information about how to contact Microsoft for international support issues, visit International Support.
  • Microsoft TechNet Security provides additional information about security in Microsoft products.


The information provided in this advisory 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.


  • V1.0 (September 1, 2009): Advisory published.
  • V2.0 (September 3, 2009): Advisory revised to add CVE-2009-2521 and to provide more information on affected software, mitigations, and workarounds.
  • V3.0 (October 13, 2009): Advisory updated to reflect publication of security bulletin.

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