{"id":"CVE-2009-4444","aliases":["EUVD-2009-4411","GHSA-4jh7-wh4m-f4pq"],"status":"published","title":"Microsoft Internet Information Services (IIS) 5.x and 6.x uses only the portion of a filename...","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.","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":0.63627,"percentile":0.99221,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2009-12-29T19:00:00Z","modified":"2026-06-16T23:13:40Z","products":[{"vendor":"microsoft","product":"internet_information_services"}],"references":[{"url":"http://www.securityfocus.com/bid/37460","tags":["vdb-entry","x_refsource_BID","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"http://securitytracker.com/id?1023387","tags":["vdb-entry","x_refsource_SECTRACK","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"http://blogs.technet.com/msrc/archive/2009/12/27/new-reports-of-a-vulnerability-in-iis.aspx","tags":["x_refsource_MISC","x_transferred","Broken Link"]},{"url":"http://secunia.com/advisories/37831","tags":["third-party-advisory","x_refsource_SECUNIA","x_transferred","Third Party Advisory"]},{"url":"http://soroush.secproject.com/downloadable/iis-semicolon-report.pdf","tags":["x_refsource_MISC","x_transferred","Third Party Advisory"]},{"url":"http://www.vupen.com/english/advisories/2009/3634","tags":["vdb-entry","x_refsource_VUPEN","x_transferred","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2009-4444"},{"url":"https://github.com/advisories/GHSA-4jh7-wh4m-f4pq"}],"sources":{"cve":[{"id":"CVE-2009-4444","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.","status":"published","published":"2009-12-29T19:00:00Z","modified":"2024-09-16T18:12:47.226Z","updated_at":"2026-11-02T14:33:24.451733Z"}],"euvd":[{"id":"EUVD-2009-4411","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.","status":"published","published":"2009-12-29T19:00:00Z","modified":"2024-09-16T18:12:47Z","updated_at":"2026-11-03T00:55:34.828317Z"}],"ghsa":[{"id":"GHSA-4jh7-wh4m-f4pq","title":"Microsoft Internet Information Services (IIS) 5.x and 6.x uses only the portion of a filename...","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.","status":"published","published":"2022-05-02T03:54:50Z","modified":"2023-01-31T05:09:08Z","updated_at":"2026-11-02T14:49:29.477947Z"}],"nvd":[{"id":"CVE-2009-4444","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.","status":"published","published":"2009-12-29T21:00:24.327Z","modified":"2026-06-16T23:13:40.793Z","cvss":[{"version":"2.0","score":6,"vector":"AV:N/AC:M/Au:S/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:01:38.33745Z"}]}}