In Sendmail, attackers can gain root privileges via SMTP by specifying an improper "mail from" address and an invalid "rcpt to" address that would cause the mail to bounce to a program.
MIME buffer overflow in Sendmail 8.8.0 and 8.8.1 gives root access.
The debug command in Sendmail is enabled, allowing attackers to execute commands as root.
MIME conversion buffer overflow in sendmail versions 8.8.3 and 8.8.4.