Multiple vulnerabilities have been discovered in lpd, shipped with various Linux and Unix distributions.
It has been reported that lpd fails to properly authenticate hostnames. This could allow an unauthenticated user to gain access to lpd services by supplying a spoofed hostname.
It is also possible for a local user to pass arguments to sendmail, through the vulnerable print daemon. This could allow an unauthorized user to execute commands with elevated privileges.
By exploiting multiple vulnerabilities in lpd, it may be possible for a remote attacker to gain root privileges on a target server.