CVE-2002-0518 Information

Description

The SYN cache (syncache) and SYN cookie (syncookie) mechanism in FreeBSD 4.5 and earlier allows remote attackers to cause a denial of service (crash) (1) via a SYN packet that is accepted using syncookies that causes a null pointer to be referenced for the socket’s TCP options or (2) by killing and restarting a process that listens on the same socket which does not properly clear the old inpcb pointer on restart.

Reference

ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-02:20.syncache.asc http://www.iss.net/security_center/static/8873.php http://www.iss.net/security_center/static/8875.php http://www.osvdb.org/6046 http://www.securityfocus.com/bid/4524