CVE-2009-2521

Name: CVE-2009-2521
Creator: NVD / NIST
Published: 2009-09-04T10:30:01.907+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 82.27%

Last modified Jun 16, 2026

CVE-2009-2521 is a vulnerability of currently unknown severity. Stack consumption vulnerability in the FTP Service in Microsoft Internet Information Services (IIS) 5.0 through 7.0 allows remote authenticated users to cause a denial of service (daemon crash) via a list (ls) -R command containing a wildcard that references a subdirectory, followed by a .. (dot dot), aka "IIS FTP Service DoS Vulnerability.". EPSS estimates a 82.27% chance of exploitation in the next 30 days.

Description

Stack consumption vulnerability in the FTP Service in Microsoft Internet Information Services (IIS) 5.0 through 7.0 allows remote authenticated users to cause a denial of service (daemon crash) via a list (ls) -R command containing a wildcard that references a subdirectory, followed by a .. (dot dot), aka "IIS FTP Service DoS Vulnerability."

Metrics

EPSS Probability

82.27%

99.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions
Microsoft	Internet Information Services	>= 5.0, <= 7.0

References

http://archives.neohapsis.com/archives/fulldisclosure/2009-09/0040.htmlBroken Link
http://support.microsoft.com/default.aspx?scid=kb%3B%5BLN%5D%3BQ975191
http://www.us-cert.gov/cas/techalerts/TA09-286A.htmlThird Party Advisory, US Government Resource
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-053Patch, Vendor Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6508Third Party Advisory
http://archives.neohapsis.com/archives/fulldisclosure/2009-09/0040.htmlBroken Link
http://support.microsoft.com/default.aspx?scid=kb%3B%5BLN%5D%3BQ975191
http://www.us-cert.gov/cas/techalerts/TA09-286A.htmlThird Party Advisory, US Government Resource
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-053Patch, Vendor Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6508Third Party Advisory

Timeline

Published: Sep 4, 2009
Last Modified: Jun 16, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2009-2521?

How severe is CVE-2009-2521?

Severity scoring for CVE-2009-2521 is pending analysis. The EPSS model estimates a 82.27% probability of exploitation in the next 30 days.

How do I fix CVE-2009-2521?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2009-2521?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST