{"id":"CVE-2021-42305","aliases":["EUVD-2021-29280","GHSA-ch43-44fr-3cm6"],"status":"published","title":"Microsoft Exchange Server Spoofing Vulnerability","description":"Microsoft Exchange Server Spoofing Vulnerability","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0787,"percentile":0.94773,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2021-11-10T00:47:38Z","modified":"2026-08-19T18:31:43Z","products":[{"vendor":"microsoft","product":"exchange_server"},{"vendor":"microsoft","product":"microsoft exchange server 2013 cumulative update 23"},{"vendor":"microsoft","product":"microsoft exchange server 2016 cumulative update 21"},{"vendor":"microsoft","product":"microsoft exchange server 2016 cumulative update 22"},{"vendor":"microsoft","product":"microsoft exchange server 2019 cumulative update 10"},{"vendor":"microsoft","product":"microsoft exchange server 2019 cumulative update 11"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42305","tags":["vendor-advisory","patch"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42305","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-42305"},{"url":"https://github.com/advisories/GHSA-ch43-44fr-3cm6"}],"sources":{"cve":[{"id":"CVE-2021-42305","title":"Microsoft Exchange Server Spoofing Vulnerability","description":"Microsoft Exchange Server Spoofing Vulnerability","status":"published","published":"2021-11-10T00:47:38Z","modified":"2026-08-19T16:27:24.438Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna"}],"updated_at":"2026-11-02T14:32:58.739039Z"}],"euvd":[{"id":"EUVD-2021-29280","description":"Microsoft Exchange Server Spoofing Vulnerability","status":"published","published":"2021-11-10T00:47:38Z","modified":"2026-08-19T16:27:24Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-02T18:01:42.811156Z"}],"ghsa":[{"id":"GHSA-ch43-44fr-3cm6","title":"Microsoft Exchange Server Spoofing Vulnerability This CVE ID is unique from CVE-2021-41349.","description":"Microsoft Exchange Server Spoofing Vulnerability This CVE ID is unique from CVE-2021-41349.","status":"published","published":"2022-05-24T19:20:21Z","modified":"2026-08-19T18:31:43Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","level":"medium"}],"updated_at":"2026-11-02T15:10:40.943268Z"}],"nvd":[{"id":"CVE-2021-42305","description":"Microsoft Exchange Server Spoofing Vulnerability","status":"published","published":"2021-11-10T01:19:49.143Z","modified":"2026-08-19T17:18:02.437Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","level":"medium","assessor":"secondary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:07:00.984108Z"}]}}