Sendmail WIZ command enabled, allowing root access.
http://www2.dataguard.no/bugtraq/1995_1/0332.html
http://www.openwall.com/lists/oss-security/2019/06/06/1
http://www.openwall.com/lists/oss-security/2019/06/05/4
http://www.cert.org/advisories/CA-1993-14.html
http://www.cert.org/advisories/CA-1990-11.html
http://www.alw.nih.gov/Security/Docs/admin-guide-to-cracking.101.html