{"id":"CVE-2021-34420","aliases":["EUVD-2021-21078","GHSA-xcgw-94hj-93r7"],"status":"published","title":"Zoom Windows installation executable signature bypass","description":"The Zoom Client for Meetings for Windows installer before version 5.5.4 does not properly verify the signature of files with .msi, .ps1, and .bat extensions. This could lead to a malicious actor installing malicious software on a customer’s computer.","severity":{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00407,"percentile":0.35464,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-347"],"published":"2021-11-11T22:59:18Z","modified":"2026-06-17T03:55:49Z","products":[{"vendor":"zoom","product":"zoom_client_for_meetings"},{"vendor":"zoom video communications inc","product":"zoom client for meetings for windows"}],"references":[{"url":"https://explore.zoom.us/en/trust/security/security-bulletin","tags":["x_refsource_MISC","x_transferred","Vendor Advisory"]},{"url":"https://medium.com/manomano-tech/a-red-team-operation-leveraging-a-zero-day-vulnerability-in-zoom-80f57fb0822e","tags":["x_refsource_MISC","x_transferred","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-34420"},{"url":"https://github.com/advisories/GHSA-xcgw-94hj-93r7"}],"sources":{"cve":[{"id":"CVE-2021-34420","title":"Zoom Windows installation executable signature bypass","description":"The Zoom Client for Meetings for Windows installer before version 5.5.4 does not properly verify the signature of files with .msi, .ps1, and .bat extensions. This could lead to a malicious actor installing malicious software on a customer’s computer.","status":"published","published":"2021-11-11T22:59:18.504Z","modified":"2024-09-16T21:03:43.509Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna"}],"updated_at":"2026-11-02T14:33:11.244759Z"}],"euvd":[{"id":"EUVD-2021-21078","description":"The Zoom Client for Meetings for Windows installer before version 5.5.4 does not properly verify the signature of files with .msi, .ps1, and .bat extensions. This could lead to a malicious actor installing malicious software on a customer’s computer.","status":"published","published":"2021-11-11T22:59:18Z","modified":"2024-09-16T21:03:43Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-03T00:55:08.578591Z"}],"ghsa":[{"id":"GHSA-xcgw-94hj-93r7","title":"The Zoom Client for Meetings for Windows installer before version 5.5.4 does not properly verify...","description":"The Zoom Client for Meetings for Windows installer before version 5.5.4 does not properly verify the signature of files with .msi, .ps1, and .bat extensions. This could lead to a malicious actor installing malicious software on a customer's computer.","status":"published","published":"2022-05-24T19:20:36Z","modified":"2023-01-30T05:03:49Z","cwes":["CWE-347"],"updated_at":"2026-11-02T14:46:55.198962Z"}],"nvd":[{"id":"CVE-2021-34420","description":"The Zoom Client for Meetings for Windows installer before version 5.5.4 does not properly verify the signature of files with .msi, .ps1, and .bat extensions. This could lead to a malicious actor installing malicious software on a customer’s computer.","status":"published","published":"2021-11-11T23:15:09.827Z","modified":"2026-06-17T03:55:49.36Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N","level":"high","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:07:00.984108Z"}]}}