---
title: "CVE-2009-4444: Microsoft Internet Information Services… | CubePath"
description: "Microsoft Internet Information Services (IIS) 5.x and 6.x uses only the portion of a filename before a ; (semicolon) character to determine the file…"
language: en
source: https://cubepath.com/security/cve/CVE-2009-4444
---

# CVE-2009-4444: Microsoft Internet Information Services… | CubePath

## Description

Microsoft Internet Information Services (IIS) 5.x and 6.x uses only the portion of a filename before a ; (semicolon) character to determine the file extension, which allows remote attackers to bypass intended extension restrictions of third-party upload applications via a filename with a (1) .asp, (2) .cer, or (3) .asa first extension, followed by a semicolon and a safe extension, as demonstrated by the use of asp.dll to handle a .asp;.jpg file.

Official description from the CVE record, published by mitre. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2009-4444)

## Key data

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.63627 (63.6% probability)

Percentile

99.2%

Scores of

Nov 10, 2026

Model

v2026.06.15

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [37460](http://www.securityfocus.com/bid/37460)  (securityfocus.com) vdb-entry
- [1023387](http://securitytracker.com/id?1023387)  (securitytracker.com) vdb-entry
- [blogs.technet.com/msrc/archive/2009/12/27/new-reports-of-a-…](http://blogs.technet.com/msrc/archive/2009/12/27/new-reports-of-a-vulnerability-in-iis.aspx)
- [37831](http://secunia.com/advisories/37831)  (secunia.com) third-party-advisory
- [soroush.secproject.com/downloadable/iis-semicolon-report.pdf](http://soroush.secproject.com/downloadable/iis-semicolon-report.pdf)
- [ADV-2009-3634](http://www.vupen.com/english/advisories/2009/3634)  (vupen.com) vdb-entry

## Timeline

1. ID reserved Dec 29, 2009
2. Record published Dec 29, 2009
3. Record last updated Sep 16, 2024

## Look up another CVE

## About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

[Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection)

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 20:01 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)