{"id":"CVE-2018-20764","aliases":["EUVD-2018-13307","GHSA-45g7-3c3h-rm3p"],"status":"published","title":"A buffer overflow exists in HelpSystems tcpcrypt on Linux, used for BoKS encrypted telnet through...","description":"A buffer overflow exists in HelpSystems tcpcrypt on Linux, used for BoKS encrypted telnet through BoKS version 6.7.1. Since tcpcrypt is setuid, exploitation leads to privilege escalation.","severity":{"version":"3.0","score":9.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-07","score":0.01185,"percentile":0.68008,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2019-02-08T17:00:00Z","modified":"2026-06-17T01:53:25Z","products":[{"vendor":"helpsystems","product":"boks"}],"references":[{"url":"https://community.helpsystems.com/knowledge-base/fox-technologies/hotfix/515/","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-20764"},{"url":"https://github.com/advisories/GHSA-45g7-3c3h-rm3p"}],"sources":{"cve":[{"id":"CVE-2018-20764","description":"A buffer overflow exists in HelpSystems tcpcrypt on Linux, used for BoKS encrypted telnet through BoKS version 6.7.1. Since tcpcrypt is setuid, exploitation leads to privilege escalation.","status":"published","published":"2019-02-08T17:00:00Z","modified":"2024-08-05T12:12:27.601Z","updated_at":"2026-11-02T14:35:00.237825Z"}],"euvd":[{"id":"EUVD-2018-13307","description":"A buffer overflow exists in HelpSystems tcpcrypt on Linux, used for BoKS encrypted telnet through BoKS version 6.7.1. Since tcpcrypt is setuid, exploitation leads to privilege escalation.","status":"published","published":"2019-02-08T17:00:00Z","modified":"2024-08-05T12:12:27Z","updated_at":"2026-11-03T02:39:29.769885Z"}],"ghsa":[{"id":"GHSA-45g7-3c3h-rm3p","title":"A buffer overflow exists in HelpSystems tcpcrypt on Linux, used for BoKS encrypted telnet through...","description":"A buffer overflow exists in HelpSystems tcpcrypt on Linux, used for BoKS encrypted telnet through BoKS version 6.7.1. Since tcpcrypt is setuid, exploitation leads to privilege escalation.","status":"published","published":"2022-05-13T01:51:07Z","modified":"2023-02-02T05:02:03Z","cvss":[{"version":"3.0","score":9.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T14:51:20.253646Z"}],"nvd":[{"id":"CVE-2018-20764","description":"A buffer overflow exists in HelpSystems tcpcrypt on Linux, used for BoKS encrypted telnet through BoKS version 6.7.1. Since tcpcrypt is setuid, exploitation leads to privilege escalation.","status":"published","published":"2019-02-08T17:29:00.303Z","modified":"2026-06-17T01:53:25.63Z","cvss":[{"version":"3.0","score":9.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"updated_at":"2026-11-02T14:04:53.728218Z"}]}}