Is CVE-2009-2521 in the CISA KEV catalog?

No. CVE-2009-2521 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2009-2521?

CVE-2009-2521 has a CVSS v2 base score of 5.0 (MEDIUM).

What is the EPSS score for CVE-2009-2521?

CVE-2009-2521 has an EPSS score of 82.27% (100th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix or mitigate CVE-2009-2521?

No published fix for CVE-2009-2521 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

CVE & CISA-KEV Catalog

CVE-2009-2521

MEDIUMEPSS 100th pctl

5.0

CVSS v2

NVD

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."

CWE-400Resource Exhaustion

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

TridentStack Control tracks known vulnerabilities across your Windows, macOS, and Linux fleet and shows the fix as soon as one is published. See how it works

CVSS v2 Vector

No CVSS vector data available.

Exploit Intelligence

82.27%probability of exploitation in 30 days

100thpercentile

Very high risk: more likely to be exploited than 100% of all known CVEs.

References

Patch1

docs.microsoft.com

Third-Party Advisory2

Other references2

Related Vulnerabilities

Other CWE-400 (Resource Exhaustion) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-44487	High	7.5	100%	KEV	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2011-3192	High	7.8	99%	-	Fix
CVE-2019-11478	Medium	5.3	95%	-	Fix
CVE-2024-25617	Medium	5.3	89%	-	Fix
CVE-2018-1000115	High	7.5	88%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.