CVE-2009-4444
Microsoft Internet Information Services (IIS) 5.x and 6.x uses only the portion of a filename...
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.
Exploit likelihood
What each source reports
NVD Score used
6.0
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.
- Record
CVE-2009-4444- CVSS 2.0
- 6.0 Medium
AV:N/AC:M/Au:S/C:P/I:P/A:P - Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2009-4444- Updated
- 2026-11-02
EUVDEUVD-2009-4411 No score
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.
- Record
EUVD-2009-4411- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-4jh7-wh4m-f4pq No score
Microsoft Internet Information Services (IIS) 5.x and 6.x uses only the portion of a filename...
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.
- Record
GHSA-4jh7-wh4m-f4pq- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2009-4444 is a medium vulnerability (CVSS 6.0) in Microsoft Internet Information Services, published December 29, 2009. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 63.6%, the 99th percentile. No source names a fixed version.
References
securityfocus.com/bid/37460
securitytracker.com/id?1023387
blogs.technet.com/msrc/archive/2009/12/27/new-reports-of-a-vulnerability-in-iis.aspx
secunia.com/advisories/37831
soroush.secproject.com/downloadable/iis-semicolon-report.pdf
vupen.com/english/advisories/2009/3634
nvd.nist.gov/vuln/detail/CVE-2009-4444
github.com/advisories/GHSA-4jh7-wh4m-f4pq