__________________________________________________________
The U.S. Department of Energy
Computer Incident Advisory Capability
___ __ __ _ ___
/ | /_\ /
\___ __|__ / \ \___
__________________________________________________________
INFORMATION BULLETIN
SUN Microsystems Solaris vold Vulnerability
August 2, 1996 17:00 GMT Number G-35
______________________________________________________________________________
PROBLEM: A vulnerability has been reported in the Volume Management
daemon, vold(1M), which manages CDROM and floppy devices.
PLATFORM: All platforms running Solaris 2.x Volume Management package
(SUNWvolu).
DAMAGE: This vulnerability may allow a local user to gain root access.
SOLUTION: CIAC recommends that sites use the workaround provided in the
bulletin below.
______________________________________________________________________________
VULNERABILITY Exploit details involving this vulnerability have been made
ASSESSMENT: publicly available.
______________________________________________________________________________
[Begin AUSCERT Bulletin]
AL-96.04 AUSCERT Alert
Vulnerability in Solaris 2.x vold
2 August 1996
------------------------------------------------------------------------------
AUSCERT has received a report of a vulnerability in the Sun Microsystems
Solaris 2.x distribution involving the Volume Management daemon, vold(1M).
This program is used to help manage CDROM and floppy devices.
This vulnerability may allow a local user to gain root privileges.
Exploit details involving this vulnerability have been made publicly
available.
At this stage, AUSCERT is not aware of any official patches. AUSCERT
recommends that sites take the actions suggested in Section 3 until official
patches are available.
------------------------------------------------------------------------------
1. Description
The Volume Management daemon, vold(1M), manages the CDROM and floppy
devices. For example, it provides the ability to automatically detect,
and then mount, removable media such as CDROMs and floppy devices.
vold is part of the Solaris 2.x Volume Management package (SUNWvolu).
It is executed as a background daemon on system startup and runs as root.
When vold detects that a CDROM or floppy has been inserted into a drive,
it is configured to automatically mount the media, making it available
to users. Part of this process includes the creation of temporary files,
which are used to allow the Openwindows File Manager, filemgr(1), to
determine that new media has been mounted. These files are created by
the action_filemgr.so shared object which is called indirectly by vold
through rmmount(1M). The handling of these files is not performed in a
secure manner. As vold is configured to access these temporary files
with root privileges, it may be possible to manipulate vold into creating
or over-writing arbitrary files on the system.
This vulnerability requires that vold be running and media managed by
vold, such as a CDROM or floppy, be physically loaded into a drive. Note
that a local user need not have physical access to the media drive to
exploit this vulnerability. It is enough to wait until somebody else
loads the drive, exploiting the vulnerability at that time.
This vulnerability is known to be present in Solaris 2.4 and Solaris 2.5.
Solaris distributions prior to Solaris 2.4 are also expected to be
vulnerable.
2. Impact
Local users may be able to create or over-write arbitrary files on the
system. This can be leveraged to gain root privileges.
3. Workaround
AUSCERT believes the workarounds given in Sections 3.1 or 3.2 will address
this vulnerability. Vendor patches may also address this vulnerability
in the future (Section 3.3).
3.1 Edit /etc/rmmount.conf
The temporary files which are susceptible to attack are created by the
/usr/lib/rmmount/action_filemgr.so.1 shared object which is called
indirectly by vold through rmmount(1M). rmmount(1M) can be
configured so that it does not create the temporary files, thereby
removing this vulnerability.
To our knowledge, configuring rmmount(1M) in this fashion will not
affect the functionality of vold. It will, however, remove the
ability of the Openwindows File Manager, filemgr(1), to automatically
detect newly mounted media.
To prevent rmmount(1M) creating temporary files, sites must edit the
/etc/rmmount.conf file and comment out (or remove) any entry which
references action_filemgr.so.
The standard /etc/rmmount.conf contains the following entries which
must be commented out (or deleted) to remove this vulnerability:
action cdrom action_filemgr.so
action floppy action_filemgr.so
After applying this workaround, an example of /etc/rmmount.conf may look
like:
# @(#)rmmount.conf 1.2 92/09/23 SMI
#
# Removable Media Mounter configuration file.
#
# File system identification
ident hsfs ident_hsfs.so cdrom
ident ufs ident_ufs.so cdrom floppy pcmem
ident pcfs ident_pcfs.so floppy pcmem
# Actions
#
# Following two lines commented out to remove vold vulnerability
#
# action cdrom action_filemgr.so
# action floppy action_filemgr.so
Note that vold does not have to be restarted for these changes to
take effect.
3.2 Remove the Volume Management system
Sites who do not require the vold functionality should remove the complete
set of Volume Management packages. These are SUNWvolg, SUNWvolu and
SUNWvolr. These packages can be removed using pkgrm(1M).
3.3 Install vendor patches
Currently, AUSCERT is not aware of any official patches which address
this vulnerability. When official patches are made available, AUSCERT
suggests that they be installed.
------------------------------------------------------------------------------
AUSCERT wishes to thanks to Leif Hedstrom, Mark McPherson(QTAC),
Marek Krawus(UQ), DFN-CERT and CERT/CC for their assistance in this matter.
------------------------------------------------------------------------------
[End AUSCERT Bulletin]
_______________________________________________________________________________
CIAC wishes to acknowledge the contributions of AUSCERT for the
information contained in this bulletin.
_______________________________________________________________________________
CIAC, the Computer Incident Advisory Capability, is the computer
security incident response team for the U.S. Department of Energy
(DOE) and the emergency backup response team for the National
Institutes of Health (NIH). CIAC is located at the Lawrence Livermore
National Laboratory in Livermore, California. CIAC is also a founding
member of FIRST, the Forum of Incident Response and Security Teams, a
global organization established to foster cooperation and coordination
among computer security teams worldwide.
CIAC services are available to DOE, DOE contractors, and the NIH. CIAC
can be contacted at:
Voice: +1 510-422-8193
FAX: +1 510-423-8002
STU-III: +1 510-423-2604
E-mail: ciac@llnl.gov
For emergencies and off-hour assistance, DOE, DOE contractor sites,
and the NIH may contact CIAC 24-hours a day. During off hours (5PM -
8AM PST), call the CIAC voice number 510-422-8193 and leave a message,
or call 800-759-7243 (800-SKY-PAGE) to send a Sky Page. CIAC has two
Sky Page PIN numbers, the primary PIN number, 8550070, is for the CIAC
duty person, and the secondary PIN number, 8550074 is for the CIAC
Project Leader.
Previous CIAC notices, anti-virus software, and other information are
available from the CIAC Computer Security Archive.
World Wide Web: http://ciac.llnl.gov/
Anonymous FTP: ciac.llnl.gov (128.115.19.53)
Modem access: +1 (510) 423-4753 (28.8K baud)
+1 (510) 423-3331 (28.8K baud)
CIAC has several self-subscribing mailing lists for electronic
publications:
1. CIAC-BULLETIN for Advisories, highest priority - time critical
information and Bulletins, important computer security information;
2. CIAC-NOTES for Notes, a collection of computer security articles;
3. SPI-ANNOUNCE for official news about Security Profile Inspector
(SPI) software updates, new features, distribution and
availability;
4. SPI-NOTES, for discussion of problems and solutions regarding the
use of SPI products.
Our mailing lists are managed by a public domain software package
called ListProcessor, which ignores E-mail header subject lines. To
subscribe (add yourself) to one of our mailing lists, send the
following request as the E-mail message body, substituting
CIAC-BULLETIN, CIAC-NOTES, SPI-ANNOUNCE or SPI-NOTES for list-name and
valid information for LastName FirstName and PhoneNumber when sending
E-mail to ciac-listproc@llnl.gov:
subscribe list-name LastName, FirstName PhoneNumber
e.g., subscribe ciac-notes OHara, Scarlett W. 404-555-1212 x36
You will receive an acknowledgment containing address, initial PIN,
and information on how to change either of them, cancel your
subscription, or get help.
PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH 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, express or implied, or assumes any
legal liability or responsibility for the accuracy, completeness, or
usefulness of any information, apparatus, 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 or the University of California, and shall not be used for
advertising or product endorsement purposes.
LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC)
G-25: SUN statd Program Vulnerability
G-26: IRIX Desktop Permissions Panel Vulnerability
G-27: SCO Kernel Security Vulnerability
G-28A: suidperl Vulnerability
G-29: dip Program Vulnerability
G-30: DEC Software Security Kits
G-31: FreeBSD Security Vulnerabilities (ppp, rdist, and rz)
G-32: HP-UX Vulnerabilities in expreserve, rpc.pcnfsd, rpc.statd
G-33: rdist vulnerability
G-34: HP-UX Vulnerabilities (netttune, SAM remote admin)
RECENT CIAC NOTES ISSUED (Previous Notes available from CIAC)
Notes 07 - 3/29/95 A comprehensive review of SATAN
Notes 08 - 4/4/95 A Courtney update
Notes 09 - 4/24/95 More on the "Good Times" virus urban legend
Notes 10 - 6/16/95 PKZ300B Trojan, Logdaemon/FreeBSD, vulnerability
in S/Key, EBOLA Virus Hoax, and Caibua Virus
Notes 11 - 7/31/95 Virus Update, Hats Off to Administrators,
America On-Line Virus Scare, SPI 3.2.2 Released,
The Die_Hard Virus
Notes 12 - 9/12/95 Securely configuring Public Telnet Services, X
Windows, beta release of Merlin, Microsoft Word
Macro Viruses, Allegations of Inappropriate Data
Collection in Win95
Notes 96-01 - 3/18/96 Java and JavaScript Vulnerabilities, FIRST
Conference Announcement, Security and Web Search
Engines, Microsoft Word Macro Virus Update
TUCoPS is optimized to look best in Firefox® on a widescreen monitor (1440x900 or better).
Site design & layout copyright © 1986-2024 AOH
