Summary
The remote host is missing updates announced in
advisory GLSA 200508-03.
Solution
All nbSMTP users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose '>=mail-mta/nbsmtp-1.0'
http://www.securityspace.com/smysecure/catid.html?in=GLSA%20200508-03 http://bugs.gentoo.org/show_bug.cgi?id=100274
http://nbsmtp.ferdyx.org/
Insight
nbSMTP is vulnerable to a format string vulnerability which may result in remote execution of arbitrary code.