{"id":"CVE-2020-13163","aliases":["EUVD-2021-0936","GHSA-4f68-49qq-h392"],"status":"published","title":"Improper certificate validation in em-imap","description":"em-imap 0.5 uses the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.","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":0.0077,"percentile":0.55937,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-295"],"published":"2020-05-19T21:22:57Z","modified":"2026-10-20T10:51:47Z","affected":[{"source":"ghsa","ecosystem":"RubyGems","package":"em-imap","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.5"}]}]},{"source":"osv","ecosystem":"RubyGems","package":"em-imap","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.5"}]}],"versions":["0.1","0.1.1","0.2","0.2.1","0.2.2","0.3.0","0.4.0","0.4.1","0.5"]}],"products":[{"vendor":"em-imap_project","product":"em-imap"}],"references":[{"url":"https://github.com/ConradIrwin/em-imap/issues/25","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence","web"]},{"url":"https://securitylab.github.com/advisories/GHSL-2020-095-conradirwin-em-imap","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-13163","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4f68-49qq-h392"},{"url":"https://github.com/ConradIrwin/em-imap","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2020-13163","description":"em-imap 0.5 uses the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.","status":"published","published":"2020-05-19T21:22:57Z","modified":"2024-08-04T12:11:19.175Z","updated_at":"2026-11-02T14:35:54.170199Z"}],"euvd":[{"id":"EUVD-2021-0936","description":"em-imap 0.5 uses the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.","status":"published","published":"2020-05-19T21:22:57Z","modified":"2024-08-04T12:11:19Z","updated_at":"2026-11-03T03:07:38.311662Z"}],"ghsa":[{"id":"GHSA-4f68-49qq-h392","title":"Improper certificate validation in em-imap","description":"em-imap 0.5 and earlier use the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.","status":"published","published":"2021-05-24T18:12:20Z","modified":"2023-09-05T21:47:53Z","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-295"],"updated_at":"2026-11-02T14:37:02.095916Z"}],"nvd":[{"id":"CVE-2020-13163","description":"em-imap 0.5 uses the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.","status":"published","published":"2020-05-19T22:15:12.09Z","modified":"2026-06-17T02:52:43.25Z","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-295"],"updated_at":"2026-11-02T14:06:00.784809Z"}],"osv":[{"id":"CVE-2020-13163","description":"em-imap 0.5 uses the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.","status":"published","published":"2020-05-19T22:15:12.09Z","modified":"2026-10-20T10:51:47.000233987Z","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":"2026-11-02T15:44:14.034736Z"},{"id":"GHSA-4f68-49qq-h392","title":"Improper certificate validation in em-imap","description":"em-imap 0.5 and earlier use the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.","status":"published","published":"2021-05-24T18:12:20Z","modified":"2024-02-16T08:24:55.783264Z","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-295"],"updated_at":"2026-11-02T15:46:36.782754Z"}]}}