CERT® Advisory CA-1990-03 Unisys U5000 /etc/passwd problemOriginal issue date: May 7, 1990
Last revised: September 17, 1997
Attached Copyright Statement
A complete revision history is at the end of this file.
The CERT/CC has recently verified several reports of unauthorized access to Internet connected Unisys systems. The intruder(s) gained access to these systems by logging into vendor supplied default accounts; accounts that had not been given passwords by the systems' owners.
Gary Garb, Corporate Computer Security Officer for Unisys Corporation, states:
"The Unisys U5000 series UNIX systems are delivered with a number of system logins. The logins are NOT password protected when the customer receives the system. Unless the customer secures these logins, the system is vulnerable to unauthorized access."
"A complete list of these logins can be found in the /etc/passwd file. Each login is described by one record in /etc/passwd which contains a number of fields separated by colons. The second field normally would contain the encrypted password. The system logins will initially have a null second field (indicated by two adjacent colons) in their descriptive records in /etc/passwd."
"The U5000/80/85/90/95 System V Administration Guide, Volume 1 (UP13679) begins with a chapter on "System Identification and Security". On page 1-2 it states, "All logins should have passwords ... Logins that are not needed should be either removed (by deleting from /etc/passwd) or blocked (by locking the login as described in the section "Locking Unused Logins" on page 1-8). The Guide contains complete instructions on controlling logins and passwords."
"It is the user's (system administrator's) responsibility to thoroughly read the Guide and to ensure the security of the system. *Securing the login entries should be of the highest priority and should be accomplished before anyone else has access to the system.*"
The CERT/CC urges administrators of Unisys systems, as well as administrators of systems provided by other vendors, to check their systems and insure all accounts are protected by passwords; passwords that are different from the default passwords provided by the vendor.
Questions regarding the security aspects of Unisys systems should be directed to:
Gary Garb, Corporate Security Officer
This document is available from: http://www.cert.org/advisories/CA-1990-03.html
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Copyright 1990 Carnegie Mellon University.
September 17,1997 Attached Copyright Statement