CVE-2009-4445
Microsoft Internet Information Services (IIS), when used in conjunction with unspecified third-party upload applications, allows remote…
- 6.0MediumCVSS base score
- 12.8%Exploitation in 30 daysEPSS · top 3.7% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Microsoft Internet Information Services (IIS), when used in conjunction with unspecified third-party upload applications, allows remote attackers to create empty files with arbitrary extensions via a filename containing an initial extension followed by a : (colon) and a safe extension, as demonstrated by an upload of a .asp:.jpg file that results in creation of an empty .asp file, related to support for the NTFS Alternate Data Streams (ADS) filename syntax. NOTE: it could be argued that this is a vulnerability in the third-party product, not IIS, because the third-party product should be applying its extension restrictions to the portion of the filename before the colon.
Timeline
ID reserved
By mitre
Published
- 15 years later
· 15 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 2.0 | Medium6.0 | AV:N/AC:M/Au:S/C:P/I:P/A:P |
- EPSS (exploitation in 30 days)
- 12.8% · top 3.7% of all CVEs (10 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.0.
Affected products
n/a
- affected n/a
References
3
- 1023387 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- http://soroush.secproject.com/downloadable/iis-semicolon-report.pdf (opens in a new tab)x_refsource_MISCx_transferred
- ms-iis-colon-security-bypass(55308) (opens in a new tab)vdb-entryx_refsource_XFx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2009-4412 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2009-4445)Record last updated .