{"id":"CVE-2023-30312","aliases":["EUVD-2023-34735"],"status":"published","description":"An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to a denial of service, impersonating the client to the server (e.g., for access to files over FTP), and impersonating the server to the client (e.g., to deliver false information from a finance website). This occurs because nf_conntrack_tcp_no_window_check is true by default.","severity":{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","level":"high","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-11","score":0.00294,"percentile":0.22208,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-203"],"published":"2024-05-28T00:00:00Z","modified":"2026-06-17T05:54:28Z","references":[{"url":"https://openwrt.org/docs/guide-developer/security","tags":["x_transferred"]},{"url":"https://www.ndss-symposium.org/ndss-paper/exploiting-sequence-number-leakage-tcp-hijacking-in-nat-enabled-wi-fi-networks/","tags":["x_transferred"]},{"url":"https://blog.apnic.net/2024/06/18/off-path-tcp-hijacking-in-nat-enabled-wi-fi-networks/","tags":["x_transferred"]},{"url":"https://news.ycombinator.com/item?id=40723150","tags":["x_transferred"]}],"sources":{"cve":[{"id":"CVE-2023-30312","description":"An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to a denial of service, impersonating the client to the server (e.g., for access to files over FTP), and impersonating the server to the client (e.g., to deliver false information from a finance website). This occurs because nf_conntrack_tcp_no_window_check is true by default.","status":"published","published":"2024-05-28T00:00:00Z","modified":"2024-11-07T11:15:57.558Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","level":"high","assessor":"adp"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T14:35:22.309324Z"}],"euvd":[{"id":"EUVD-2023-34735","description":"An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to a denial of service, impersonating the client to the server (e.g., for access to files over FTP), and impersonating the server to the client (e.g., to deliver false information from a finance website). This occurs because nf_conntrack_tcp_no_window_check is true by default.","status":"published","published":"2024-05-28T00:00:00Z","modified":"2024-11-07T11:15:57Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","level":"high"}],"updated_at":"2026-11-03T00:05:08.721426Z"}],"nvd":[{"id":"CVE-2023-30312","description":"An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to a denial of service, impersonating the client to the server (e.g., for access to files over FTP), and impersonating the server to the client (e.g., to deliver false information from a finance website). This occurs because nf_conntrack_tcp_no_window_check is true by default.","status":"published","published":"2024-05-28T22:15:11.247Z","modified":"2026-06-17T05:54:28.297Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-203"],"updated_at":"2026-11-02T14:09:17.205287Z"}]}}