{"id":"CVE-2021-21991","aliases":["EUVD-2021-9162","GHSA-h338-w3fh-545j"],"status":"published","title":"The vCenter Server contains a local privilege escalation vulnerability due to the way it handles...","description":"The vCenter Server contains a local privilege escalation vulnerability due to the way it handles session tokens. A malicious actor with non-administrative user access on vCenter Server host may exploit this issue to escalate privileges to Administrator on the vSphere Client (HTML5) or vCenter Server vSphere Web Client (FLEX/Flash).","severity":{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.00316,"percentile":0.24918,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-269"],"published":"2021-09-22T18:59:08Z","modified":"2026-06-17T03:36:30Z","products":[{"vendor":"vmware","product":"cloud_foundation"},{"vendor":"vmware","product":"vcenter_server"}],"references":[{"url":"https://www.vmware.com/security/advisories/VMSA-2021-0020.html","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21991"},{"url":"https://github.com/advisories/GHSA-h338-w3fh-545j"}],"sources":{"cve":[{"id":"CVE-2021-21991","description":"The vCenter Server contains a local privilege escalation vulnerability due to the way it handles session tokens. A malicious actor with non-administrative user access on vCenter Server host may exploit this issue to escalate privileges to Administrator on the vSphere Client (HTML5) or vCenter Server vSphere Web Client (FLEX/Flash).","status":"published","published":"2021-09-22T18:59:08Z","modified":"2024-08-03T18:30:23.658Z","updated_at":"2026-11-02T14:33:00.137099Z"}],"euvd":[{"id":"EUVD-2021-9162","description":"The vCenter Server contains a local privilege escalation vulnerability due to the way it handles session tokens. A malicious actor with non-administrative user access on vCenter Server host may exploit this issue to escalate privileges to Administrator on the vSphere Client (HTML5) or vCenter Server vSphere Web Client (FLEX/Flash).","status":"published","published":"2021-09-22T18:59:08Z","modified":"2024-08-03T18:30:23Z","updated_at":"2026-11-03T03:25:04.094929Z"}],"ghsa":[{"id":"GHSA-h338-w3fh-545j","title":"The vCenter Server contains a local privilege escalation vulnerability due to the way it handles...","description":"The vCenter Server contains a local privilege escalation vulnerability due to the way it handles session tokens. A malicious actor with non-administrative user access on vCenter Server host may exploit this issue to escalate privileges to Administrator on the vSphere Client (HTML5) or vCenter Server vSphere Web Client (FLEX/Flash).","status":"published","published":"2022-05-24T19:15:24Z","modified":"2023-01-27T05:03:42Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-269"],"updated_at":"2026-11-02T14:42:18.285263Z"}],"nvd":[{"id":"CVE-2021-21991","description":"The vCenter Server contains a local privilege escalation vulnerability due to the way it handles session tokens. A malicious actor with non-administrative user access on vCenter Server host may exploit this issue to escalate privileges to Administrator on the vSphere Client (HTML5) or vCenter Server vSphere Web Client (FLEX/Flash).","status":"published","published":"2021-09-22T19:15:09.093Z","modified":"2026-06-17T03:36:30.933Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":4.6,"vector":"AV:L/AC:L/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:06:58.933037Z"}]}}