{"id":"CVE-2020-27631","details":"In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.","modified":"2026-07-08T17:57:33.370776Z","published":"2023-10-10T17:15:10.453Z","references":[{"type":"ADVISORY","url":"https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01"},{"type":"ADVISORY","url":"https://www.forescout.com"},{"type":"ADVISORY","url":"https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/oryx-embedded/cyclonetcp","events":[{"introduced":"21fb9364b397deac4cb940c733e09cf34ec57b9c"},{"last_affected":"21fb9364b397deac4cb940c733e09cf34ec57b9c"}],"database_specific":{"cpe":"cpe:2.3:a:oryx-embedded:cyclonetcp:1.9.6:*:*:*:*:*:*:*","extracted_events":[{"introduced":"1.9.6"},{"last_affected":"1.9.6"}],"source":"CPE_STRING"}}],"versions":["1.9.6","v1.9.6"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-27631.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}