Microsoft Internet Information Services (IIS) 5.x and 6.x uses only the portion of a filename before a ; (semicolon) character to…

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.

Scores

EPSS (exploitation in 30 days)

63.6% · top 0.8% of all CVEs (6 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.0.

Weakness

• n/a

Affected products

• n/a

  • affected n/a

References (6)

• 37460 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
• 1023387 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
• http://blogs.technet.com/msrc/archive/2009/12/27/new-reports-of-a-vulnerability-in-iis.aspx (opens in a new tab)x_refsource_MISCx_transferred
• 37831 (opens in a new tab)third-party-advisoryx_refsource_SECUNIAx_transferred
• http://soroush.secproject.com/downloadable/iis-semicolon-report.pdf (opens in a new tab)x_refsource_MISCx_transferred
• ADV-2009-3634 (opens in a new tab)vdb-entryx_refsource_VUPENx_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)
• 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

[![CVE-2009-4444](https://trackcve.app/badge/CVE-2009-4444.svg)](https://trackcve.app/cve/CVE-2009-4444)

Record last updated 16 Sept 2024, 18:12 UTC.