-----BEGIN PGP SIGNED MESSAGE-----
__________________________________________________________
The U.S. Department of Energy
Computer Incident Advisory Capability
___ __ __ _ ___
/ | /_\ /
\___ __|__ / \ \___
__________________________________________________________
INFORMATION BULLETIN
SGI IRIX startmidi/stopmidi Vulnerability
February 13, 1997 00:00 GMT Number H-28
______________________________________________________________________________
PROBLEM: A vulnerability exists in the startmidi(1)/stopmidi(1) program.
PLATFORM: All SGI systems running IRIX 5.2, 5.3, 6.0, 6.0.1, and 6.1
with an IRIS Digital Media Execution Environment.
DAMAGE: This vulnerability may allow local users to gain root
privileges or perform a denial of service attack.
SOLUTION: Until patches are available, take the steps outlined in section
3 as soon as possible.
______________________________________________________________________________
VULNERABILITY Exploit details involving this vulnerability have been made
ASSESSMENT: publicly available.
______________________________________________________________________________
[ Start AUSCERT Advisory ]
===========================================================================
AA-97.05 AUSCERT Advisory
SGI IRIX startmidi/stopmidi Vulnerability
11 February 1997
Last Revised: --
- ----------------------------------------------------------------------------
AUSCERT has received information that a vulnerability exists in the
startmidi(1)/stopmidi(1) program which is part of the SGI IRIS Digital
Media Execution Environment.
This vulnerability may allow local users to gain root privileges or
perform a denial of service attack.
Exploit information has been made publicly available.
Currently there are no vendor patches available that address this
vulnerability. AUSCERT recommends that sites take the steps outlined
in section 3 as soon as possible.
This advisory will be updated as more information becomes available.
- ----------------------------------------------------------------------------
1. Description
The SGI IRIS Digital Media Execution Environment contains the basic
system components necessary to support audio, MIDI (Musical Instrument
Digital Interface), and video applications on an IRIS workstation.
One part of this product is the MIDI Execution Environment, which
among other things, contains the startmidi/stopmidi program. stopmidi
is a symbolic link to the startmidi program.
Before any MIDI applications can be run, it is usually necessary to
configure the serial ports for use with MIDI. startmidi initializes
the serial ports and links them to the MIDI streams driver. stopmidi
disables MIDI on the specified device.
During the execution of startmidi, files are created in an insecure
manner with insecure permissions. As this program executes with root
privileges, it is possible for local users to create or truncate
arbitrary files on the system. It also possible to alter the contents
of these temporary files, which may allow users to perform a denial
of service attack.
Exploit information has been made publicly available.
The default location for startmidi/stopmidi is /usr/sbin/.
At this stage, IRIX 5.2, 5.3, 6.0, 6.0.1, and 6.1 are known to contain
this vulnerability. Sites can determine the version of the operating
system with the command:
%
/sbin/uname -a
2. Impact
Local users may be able to create or truncate arbitrary files on
the system, which may be leveraged to gain root access. They may
also be able to change the contents of temporary files, allowing a
denial of service attack.
3. Workarounds/Solution
AUSCERT recommends that sites prevent the exploitation of this
vulnerability in startmidi/stopmidi by immediately applying the
workaround given in Section 3.1. If the MIDI Execution Environment
is not required, it is recommended that sites remove it from their
systems (Section 3.2).
Currently there are no vendor patches available that address this
vulnerability. AUSCERT recommends that official vendor patches be
installed when they are made available.
3.1 Remove setuid and execute permissions
Until official vendor patches are made available, sites should remove
the setuid root and execute permissions from startmidi. To do this,
the following command should be run as root:
# /bin/chmod 400 /usr/sbin/startmidi
# /bin/ls -l /usr/sbin/startmidi
-r-------- 1 root sys 18608 Nov 22 1994 /usr/sbin/startmidi
Note that this will remove the ability for any user to run the
startmidi or stopmidi program. If only the setuid permissions are
removed, it is still possible for users to gain privileges when
startmidi is executed by the root user.
3.2 Remove the MIDI Execution Environment
If the MIDI Execution Environment is no longer needed, sites are
encouraged to remove it completely from their systems. This can be
done by running, as root, the GUI software management tool, swmgr, or
the command:
# /usr/sbin/versions remove dmedia_eoe.sw.midi
Sites can check that the package has been removed with the command:
# /usr/sbin/versions dmedia_eoe.sw.midi
4. Additional measures
Most Unix systems ship with numerous programs which have setuid or
setgid privileges. Often the functionality supplied by these
privileged programs is not required by many sites. The large number
of privileged programs that are shipped by default are to cater for
all possible uses of the system.
AUSCERT encourages sites to examine all the setuid/setgid programs
and determine the necessity of each program. If a program does not
absolutely require the setuid/setgid privileges to operate (for
example, it is only run by the root user), the setuid/setgid
privileges should be removed. Furthermore, if a program is not
required at your site, then all execute permissions should be removed.
A sample command to find all setuid/setgid programs is (run as root):
# find / \( -perm -4000 -o -perm -2000 \) -exec ls -ld {} \;
It is AUSCERT's experience that many vulnerability are being
discovered in setuid/setgid programs which are not necessary for the
correct operation of most systems. Sites can increase their security
by removing unnecessary setuid/setgid programs.
For example, the functionality provided by the startmidi/stopmidi
program is not needed by most sites. If sites had previously disabled
this program, they would not have been susceptible to this latest
vulnerability.
===========================================================================
[ End AUSCERT Advisory ]
_______________________________________________________________________________
CIAC wishes to acknowledge the contributions of AUSCERT and Silicon Graphics 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 via WWW at http://www.first.org/.
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)
H-18: Denial-of-Service Attack via ping
H-19: HP Software Installation Programs Vulnerability
H-20: Vulnerability in IRIX csetup
H-21: HP Security Vulnerabilities (newgrp, authentication, passwor
H-22: talkd Buffer Overrun Vulnerability
H-23: Sendmail MIME Conversion Buffer Overrun Vulnerability
H-24: IBM AIX(r) "gethostbyname()" Buffer Overrun Vulnerability
H-25: Vulnerability in rlogin/term
H-26: FreeBSD setlocale() Vulnerability
H-27: HP-UX vgdisplay Buffer Overrun Vulnerability
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
-----BEGIN PGP SIGNATURE-----
Version: 2.6.2
iQCVAwUBMxtc3LnzJzdsy3QZAQHnugQA0ldUaY6qHvoT4/ekthiA50b+/DOUOnJq
Q8XdWy72dKaa0AZASKo/AFtklLbp4wY5LXAzvC7ErBmXma0YIXOTHwRByB5hVSYh
cWqMm4KBUkhoB0Euflb1Am4jqUtpeKEYF0tntVxvobBoCsrWIauq5nwIg6ntdNc8
9jDYendNdGU=
=+Xd2
-----END PGP SIGNATURE-----
TUCoPS is optimized to look best in Firefox® on a widescreen monitor (1440x900 or better).
Site design & layout copyright © 1986-2024 AOH
