The remote mail server is affected by a buffer overflow vulnerability.
Description :
The remote host is running the Mercury Mail Transport System, a free
suite of server products for Windows and Netware associated with
Pegasus Mail.
The version of Mercury Mail installed on the remote host includes an
SMTP server that is affected by a buffer overflow flaw. Using a
specially-crafted AUTH CRAM-MD5 request, an unauthenticated remote
attacker can leverage this issue to crash the remote application and
even execute arbitrary code remotely, subject to the privileges under
which the application runs.