CVE-2023-30312

High severity, CVSS 7.3. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Published 2024-05-28. Last modified 2026-06-17.