CVE-2003-1230

Medium severity, CVSS 6.4. EPSS: 1.4% chance of exploitation in the next 30 days.

The implementation of SYN cookies (syncookies) in FreeBSD 4.5 through 5.0-RELEASE-p3 uses only 32-bit internal keys when generating syncookies, which makes it easier for remote attackers to conduct brute force ISN guessing attacks and spoof legitimate traffic.

Published 2003-12-31. Last modified 2026-06-16.