{"id":"CVE-2009-4445","aliases":["EUVD-2009-4412","GHSA-vgvh-f7c3-rv4v"],"status":"published","title":"Microsoft Internet Information Services (IIS), when used in conjunction with unspecified third...","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.","severity":{"version":"2.0","score":6,"vector":"AV:N/AC:M/Au:S/C:P/I:P/A:P","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.12757,"percentile":0.96301,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20"],"published":"2009-12-29T19:00:00Z","modified":"2026-06-16T23:13:40Z","products":[{"vendor":"microsoft","product":"internet_information_services"}],"references":[{"url":"http://securitytracker.com/id?1023387","tags":["vdb-entry","x_refsource_SECTRACK","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"http://soroush.secproject.com/downloadable/iis-semicolon-report.pdf","tags":["x_refsource_MISC","x_transferred","Third Party Advisory"]},{"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/55308","tags":["vdb-entry","x_refsource_XF","x_transferred"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2009-4445"},{"url":"https://github.com/advisories/GHSA-vgvh-f7c3-rv4v"}],"sources":{"cve":[{"id":"CVE-2009-4445","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.","status":"published","published":"2009-12-29T19:00:00Z","modified":"2024-08-07T07:01:20.343Z","updated_at":"2026-11-02T14:33:24.451733Z"}],"euvd":[{"id":"EUVD-2009-4412","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.","status":"published","published":"2009-12-29T19:00:00Z","modified":"2024-08-07T07:01:20Z","updated_at":"2026-11-03T01:39:10.134983Z"}],"ghsa":[{"id":"GHSA-vgvh-f7c3-rv4v","title":"Microsoft Internet Information Services (IIS), when used in conjunction with unspecified third...","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.","status":"published","published":"2022-05-02T03:54:50Z","modified":"2023-01-31T05:08:14Z","cwes":["CWE-20"],"updated_at":"2026-11-02T14:49:21.861418Z"}],"nvd":[{"id":"CVE-2009-4445","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.","status":"published","published":"2009-12-29T21:00:24.453Z","modified":"2026-06-16T23:13:40.907Z","cvss":[{"version":"2.0","score":6,"vector":"AV:N/AC:M/Au:S/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:01:38.33745Z"}]}}