{"id":"CVE-2021-21994","aliases":["EUVD-2021-9165","GHSA-4643-h6pq-84f9"],"status":"published","title":"SFCB (Small Footprint CIM Broker) as used in ESXi has an authentication bypass vulnerability. A...","description":"SFCB (Small Footprint CIM Broker) as used in ESXi has an authentication bypass vulnerability. A malicious actor with network access to port 5989 on ESXi may exploit this issue to bypass SFCB authentication by sending a specially crafted request.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.01167,"percentile":0.67578,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":false},"cwes":["CWE-287"],"published":"2021-07-13T18:05:43Z","modified":"2026-06-17T03:36:31Z","exploits":[{"source":"pocgithub","id":"mreza-en/cve-2021-21994_POC","title":"mreza-en/cve-2021-21994_POC","date":"2026-08-15","url":"https://github.com/mreza-en/cve-2021-21994_POC"}],"products":[{"vendor":"vmware","product":"cloud_foundation"},{"vendor":"vmware","product":"esxi"}],"references":[{"url":"https://www.vmware.com/security/advisories/VMSA-2021-0014.html","tags":["x_refsource_MISC","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21994"},{"url":"https://github.com/advisories/GHSA-4643-h6pq-84f9"}],"sources":{"cve":[{"id":"CVE-2021-21994","description":"SFCB (Small Footprint CIM Broker) as used in ESXi has an authentication bypass vulnerability. A malicious actor with network access to port 5989 on ESXi may exploit this issue to bypass SFCB authentication by sending a specially crafted request.","status":"published","published":"2021-07-13T18:05:43Z","modified":"2024-08-03T18:30:23.556Z","updated_at":"2026-11-02T14:33:00.488332Z"}],"euvd":[{"id":"EUVD-2021-9165","description":"SFCB (Small Footprint CIM Broker) as used in ESXi has an authentication bypass vulnerability. A malicious actor with network access to port 5989 on ESXi may exploit this issue to bypass SFCB authentication by sending a specially crafted request.","status":"published","published":"2021-07-13T18:05:43Z","modified":"2024-08-03T18:30:23Z","updated_at":"2026-11-03T03:25:04.094929Z"}],"ghsa":[{"id":"GHSA-4643-h6pq-84f9","title":"SFCB (Small Footprint CIM Broker) as used in ESXi has an authentication bypass vulnerability. A...","description":"SFCB (Small Footprint CIM Broker) as used in ESXi has an authentication bypass vulnerability. A malicious actor with network access to port 5989 on ESXi may exploit this issue to bypass SFCB authentication by sending a specially crafted request.","status":"published","published":"2022-05-24T19:07:32Z","modified":"2023-01-30T05:00:41Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:46:15.397604Z"}],"nvd":[{"id":"CVE-2021-21994","description":"SFCB (Small Footprint CIM Broker) as used in ESXi has an authentication bypass vulnerability. A malicious actor with network access to port 5989 on ESXi may exploit this issue to bypass SFCB authentication by sending a specially crafted request.","status":"published","published":"2021-07-13T19:15:09.327Z","modified":"2026-06-17T03:36:31.263Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":6.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:06:55.747384Z"}]}}