COMMAND

    sendmail(8)

SYSTEMS AFFECTED

    All  BSD  derived  systems,  and/or  systems  using  BSD  sendmail
    versions older than 5.59.

PROBLEM

    Systems using this sendmail program or derivations of it, may have
    the  DEBUG  command  enabled.  This  allows  remote  execution  of
    commands.

SOLUTION

    This is hopefully long gone from nowadays sendmail.