NASIRC BULLETIN #93-10 December 16, 1993 Solaris System Startup Vulnerability ======================================================= ==================== __ __ __ ___ ___ ____ ____ /_/\ /_/| /_/ / _/\ /_/| / __/ \ / __/\ | |\ \| || / \ \ | /\/ | || | /\ \/ | | \/ | ||\ \ || / /\ \ \ \ \ | || |_\/ /\ | | | || \ \|| / /--\ \ \ /\_\\ | || | |\ \ \ | \_/\ |_|/ \_|//_/ \_\/ \/__/ |_|/ |_| \_\/ \___\/ NASA Automated Systems Incident Response Capability ======================================================= ==================== NASIRC has received information concerning a potential security problem involving Solaris 2.x systems and Solaris x86. The problem does not exist in sun3 architectures. If fsck(8) fails during system boot, a privileged shell is run on the system console. This vulnerability allows a user, sitting at the console, to gain root access to the system. A simple change to two system scripts can be used to close this potential security vulnerability. The modified shells will cause the system to run the privileged shell only if the user at the console enters the correct root password. The changes, described below, have been integrated into the upcoming Solaris release. If you wish to make the change on your system, edit both: /sbin/rcS and /sbin/mountall changing every occurrence of: /sbin/sh < /dev/console to /sbin/sulogin < /dev/console As distributed by Sun, /sbin/rcS contains one occurrence of this string, at line 152; and /sbin/mountall contains two, on at line 66 an done at line 250. Once this change has been made, sulogin will request the root password in the event fsck(8) fails, before starting a privileged shell. The success or failure of sulogin will be logged in /var/adm/sulog. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= NASIRC ACKNOWLEDGES: Sun Microsystems, Inc. for their reporting and coordination of solutions to this problem =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= The NASIRC online archive system is available via anonymous ftp. Just ftp to nasirc.nasa.gov and login as anonymous. You will be required to enter your valid e-mail address. Once there you can access the following information: /toolkits ! contains automated toolkit software /bulletins ! contains NASIRC bulletins Information maintained in these directories will be updated on a continuous basis with relevant software and information. Contact the NASIRC Helpdesk for more information and assistance with toolkits or security measures. ======================================================= ================ For further assistance, please contact the NASIRC Helpdesk: Phone: 1-800-7-NASIRC Fax: 1-301-306-1010 Internet Email: nasirc@nasa.gov 24 Hour/Emergency Pager: 1-800-759-7243/Pin:5460866 ======================================================= ================ This bulletin may be forwarded without restrictions to sites and system administrators within the NASA community ----------------- PLEASE NOTE: Users outside of the NASA community may receive NASIRC bulletins. If you are not part of the NASA community, please contact your agency's response team to report incidents. Your agency's team will coordinate with NASIRC, who will ensure the proper internal NASA team(s) are notified. NASIRC is a member of the Forum of Incident Response and Security Teams (FIRST), a world-wide organization which provides for coordination between incident response teams in handling computer-security-related issues. A list of FIRST member organizations and their constituencies can be obtained by sending email to docserver@first.org with an empty subject line and a message body containing the line: send first-contacts.