mail.local in NetBSD versions 6.0 through 6.0.6, 6.1 through 6.1.5, and 7.0 allows local users to change ownership of or append data to arbitrary files on the target system via a symlink attack on the user mailbox.
akat1.pl/?id=2
ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2016-006.txt.asc
packetstormsecurity.com/files/138021/NetBSD-mail.local-8-Local-Root.html
www.rapid7.com/db/modules/exploit/unix/local/netbsd_mail_local
www.securityfocus.com/bid/92101
www.securitytracker.com/id/1036429
www.exploit-db.com/exploits/40141/
www.exploit-db.com/exploits/40385/