{"id":"CVE-2021-3547","aliases":["EUVD-2021-26858","GHSA-2cgw-c87g-ww8q"],"status":"published","title":"OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the...","description":"OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.","severity":{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.01238,"percentile":0.69359,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-287","CWE-295","CWE-305"],"published":"2021-07-12T10:35:52Z","modified":"2026-10-24T10:31:01Z","products":[{"vendor":"openvpn","product":"openvpn"},{"vendor":"openvpn","product":"openvpn 3 core library"}],"references":[{"url":"https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements","tags":["x_refsource_MISC","x_transferred","Vendor Advisory","advisory"]},{"url":"https://community.openvpn.net/openvpn/wiki/CVE-2021-3547","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-3547"},{"url":"https://github.com/advisories/GHSA-2cgw-c87g-ww8q"}],"sources":{"cve":[{"id":"CVE-2021-3547","description":"OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.","status":"published","published":"2021-07-12T10:35:52Z","modified":"2024-08-03T17:01:06.568Z","cwes":["CWE-305"],"updated_at":"2026-11-02T14:33:04.020035Z"}],"euvd":[{"id":"EUVD-2021-26858","description":"OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.","status":"published","published":"2021-07-12T10:35:52Z","modified":"2024-08-03T17:01:06Z","updated_at":"2026-11-03T03:25:12.535968Z"}],"ghsa":[{"id":"GHSA-2cgw-c87g-ww8q","title":"OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the...","description":"OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.","status":"published","published":"2022-05-24T19:07:31Z","modified":"2023-01-30T05:02:00Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-287","CWE-295"],"updated_at":"2026-11-02T14:46:32.185763Z"}],"nvd":[{"id":"CVE-2021-3547","description":"OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.","status":"published","published":"2021-07-12T11:15:08.233Z","modified":"2026-06-17T04:05:19.547Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"primary"},{"version":"2.0","score":5.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-305","CWE-295"],"updated_at":"2026-11-02T14:06:55.259633Z"}],"osv":[{"id":"CVE-2021-3547","description":"OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.","status":"published","published":"2021-07-12T11:15:08.233Z","modified":"2026-10-24T10:31:01.021261648Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:44:20.13324Z"}]}}