{"id":"CVE-2020-27631","aliases":["EUVD-2020-20138","GHSA-gvwh-h9wm-jvg4"],"status":"published","title":"In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.","description":"In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.01083,"percentile":0.6548,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-330"],"published":"2023-10-10T00:00:00Z","modified":"2026-10-24T10:30:27Z","products":[{"vendor":"oryx-embedded","product":"cyclonetcp"}],"references":[{"url":"https://www.forescout.com","tags":["x_transferred","Third Party Advisory","advisory"]},{"url":"https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01","tags":["x_transferred","Third Party Advisory","US Government Resource","advisory"]},{"url":"https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/","tags":["x_transferred","Third Party Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-27631"},{"url":"https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks"},{"url":"https://github.com/advisories/GHSA-gvwh-h9wm-jvg4"}],"sources":{"cve":[{"id":"CVE-2020-27631","description":"In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.","status":"published","published":"2023-10-10T00:00:00Z","modified":"2024-09-19T15:28:15.213Z","updated_at":"2026-11-02T14:35:53.236501Z"}],"euvd":[{"id":"EUVD-2020-20138","description":"In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.","status":"published","published":"2023-10-10T00:00:00Z","modified":"2024-09-19T15:28:15Z","updated_at":"2026-11-03T00:28:19.06347Z"}],"ghsa":[{"id":"GHSA-gvwh-h9wm-jvg4","title":"In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.","description":"In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.","status":"published","published":"2023-10-10T18:31:32Z","modified":"2024-04-04T08:29:49Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-330"],"updated_at":"2026-11-02T14:56:58.612577Z"}],"nvd":[{"id":"CVE-2020-27631","description":"In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.","status":"published","published":"2023-10-10T17:15:10.453Z","modified":"2026-06-17T03:09:23.88Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-330"],"updated_at":"2026-11-02T14:06:47.910346Z"}],"osv":[{"id":"CVE-2020-27631","description":"In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.","status":"published","published":"2023-10-10T17:15:10.453Z","modified":"2026-10-24T10:30:27.222164213Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:16.248747Z"}]}}