The Sendmail 8.12.3 package in Debian GNU/Linux 3.0 does not securely create temporary files, which could allow local users to gain additional privileges via (1) expn, (2) checksendmail, or (3) doublebounce.pl.
https://bugs.gentoo.org/show_bug.cgi?id=235770
http://www.openwall.com/lists/oss-security/2008/10/30/2
http://www.debian.org/security/2003/dsa-305
http://dev.gentoo.org/~rbu/security/debiantemp/sendmail-base