In order to improve the security of our departmental computing systems, we are planning to limit unsecured access to our UNIX machines from outside the department. You will probably be affected by these changes if you connect to our systems from home or while traveling and use applications such as telnet or ftp, or use a mail-reading program that uses POP or IMAP (e.g., Netscape Messenger).
The following changes to remote services provided by CS UNIX machines will be made during the summer or 2002.
Remote shell access (rsh/rlogin/telnet)
Update: Telnet service turned off 17 July 2002
Update: Rsh/rlogin restrictions implemented 22 July 2002
External telnet and rsh/rlogin connections will not be allowed. Remote shell access will be available through SSH (1 or 2) only. Rsh and rlogin will still be available from CS network machines. Even though rsh and rlogin will still be available internally, the use of SSH is strongly encouraged.
Remote mail access (POP/IMAP)
Update: POP/IMAP restrictions implemented 29 July 2002
External connections to non-encrypted POP3 and IMAP services will be disallowed. All external POP3 and IMAP connections will require SSL.
Remote finger requests
Update: Remote finger turned off 10 July 2002
The remote finger service will be disabled. It is used increasingly to gather information used to send SPAM to CS users and may potentially be used to gather information for intrusion attempts. Based on several local inquiries it also reveals too much information for people. The finger and who commands will still be available on the local machine.
Remote file transfers (FTP)
Update: FTP restrictions implemented 18 June 2002
External FTP connections will only be allowed to ftp.cs.purdue.edu, our public FTP server. Remote file access will be available through sftp. Our SSH servers are configured to support this extention.
In the coming weeks we will try to identify those users that are using the insecure protocols for connections. However, if we miss you, or you would like help in switching to a secure mechanism, please let us know (send mail to software@cs.purdue.edu).
ADDENDUM: See our Remote access to CS Facilities page for freeware software.
Facilties Software Staff
