The line printer daemon (lpd) in the lpr package in multiple Linux operating systems allows local users to gain root privileges by causing sendmail to execute with arbitrary command line arguments, as demonstrated using the -C option to specify a configuration file.
The line printer daemon (lpd) in the lpr package in multiple Linux operating systems authenticates by comparing the reverse-resolved hostname of the local machine to the hostname of the print server as returned by gethostname, which allows remote attackers to bypass intended access controls by modifying the DNS for the attacking IP.
Versions of rpcbind including Linux, IRIX, and Wietse Venema's rpcbind allow a remote attacker to insert and delete entries by spoofing a source address.
The asynchronous I/O facility in 4.4 BSD kernel does not check user credentials when setting the recipient of I/O notification, which allows local users to cause a denial of service by using certain ioctl and fcntl calls to cause the signal to be sent to an arbitrary process ID.