_____________________________________________________ The Computer Incident Advisory Capability ___ __ __ _ ___ / | / \ / \___ __|__ /___\ \___ _____________________________________________________ INFORMATION BULLETIN Solaris 2.x expreserve patches available July 1, 1993 0900 PDT Number D-18 __________________________________________________________________________ PROBLEM: The expreserve utility allows unauthorized access to system files. PLATFORM: Sun workstations running Solaris 2.0, 2.1, and 2.2 (SunOS 5.0, 5.1, and 5.2). DAMAGE: Local users can gain root access. SOLUTION: Disable expreserve immediately, then install patch from Sun. __________________________________________________________________________ Critical Information about the expreserve Vulnerability CIAC has learned that Sun Microsystems has released three new security patches for Solaris 2.x systems to remove the vulnerability in the expreserve utility described in CIAC Advisory D-16. This vulnerability allows local users to overwrite the contents of any file, regardless of file ownership, and can be used to obtain root access to the system. CIAC continues to recommend that the expreserve utility be disabled until the appropriate patched version can be installed. Disabling expreserve -------------------- To prevent use of the expreserve utility, execute the following command as root: /bin/chmod a-x /usr/lib/expreserve The expreserve command normally is used to recover editor files when vi, ex, or edit terminate unexpectedly. Disabling expreserve will disable this recovery feature. Users of these editors should be advised of this temporary change and encouraged to save their work frequently. Patching Solaris 2.x (SunOS 5.x) -------------------------------- Sun Microsystems has released three Solaris 2.x expreserve patches: Checksums Patch ID Solaris Version /usr/bin/sum /usr/ucb/sum --------- --------------- ------------ ------------ 101119-01 Solaris 2.0 61863 54 47944 27 101089-01 Solaris 2.1 4501 54 07227 27 101090-01 Solaris 2.2 44985 54 02491 27 These patches, along with all other Sun security patches, are available both through your local Sun Answer Center and anonymous ftp. In the U.S., ftp to ftp.uu.net and retrieve the patches from the directory /systems/sun/sun-dist. In Europe, ftp to mcsun.eu.net and retrieve the patches from the /sun/fixes directory. After retrieving a patch, its checksum may be verified using the sum command. Note that Sun Microsystems occasionally updates patch files, resulting in a changed checksum. Should you find that your checksums differ, please contact CIAC or Sun Microsystems for verification before installing the patch. To install the patch on your system, follow the instructions contained in the README file that accompanies the patch. For additional information or assistance, please contact CIAC at (510)422-8193 or send E-mail to ciac@llnl.gov. FAX messages to (510)423-8002. Previous CIAC bulletins and other information are available via anonymous FTP from irbis.llnl.gov (IP address 128.115.19.60). CIAC wishes to acknowledge the contributions of Sun Microsystems in the preparation of this bulletin. PLEASE NOTE: Many users outside of the DOE and ESnet computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. 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. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government nor the University of California, and shall not be used for advertising or product endorsement purposes.