CERT^® Advisory CA-1999-08 Buffer Overflow Vulnerability in Calendar Manager Service Daemon, rpc.cmsd

A complete revision history is at the end of this file.

Systems Affected

• Systems running the Calendar Manager Service daemon, often named rpc.cmsd

I. Description

A buffer overflow vulnerability has been discovered in the Calendar Manager Service daemon, rpc.cmsd. The rpc.cmsd daemon is frequently distributed with the Common Desktop Environment (CDE) and Open Windows.

II. Impact

Remote and local users can execute arbitrary code with the privileges of the rpc.cmsd daemon, typically root. Under some configurations rpc.cmsd runs with an effective userid of daemon, while retaining root privileges.

This vulnerability is being exploited in a significant number of incidents reported to the CERT/CC. An exploit script was posted to BUGTRAQ. For more information about attacks using various RPC services please see CERT® Incident Note IN-99-04 http://www.cert.org/incident_notes/IN-99-04.html

III. Solution

Install a patch from your vendor

Appendix A contains information provided by vendors for this advisory. We will update the appendix as we receive more information. If you do not see your vendor's name, the CERT/CC did not hear from that vendor. Please contact your vendor directly.

We will update this advisory as more information becomes available. Please check the CERT/CC Web site for the most current revision.

Disable the rpc.cmsd daemon

If you are unable to apply patches to correct this vulnerability, you may wish to disable the rpc.cmsd daemon. If you disable rpc.cmsd, it may affect your ability to manage calendars.

Appendix A: Vendor Information

Fujitsu's UXP/V operating system is not vulnerable.

Patches are available. Please see the following document for details:

HPSBUX9908-102 Security Vulnerability in rpc.cmsd

AIX is not vulnerable to the rpc.cmsd remote buffer overflow.
IBM and AIX are registered trademarks of International Business Machines Corporation.

SCO is investigating this problem. The following SCO product contains CDE and is potentially vulnerable:

• SCO UnixWare 7

The following SCO products do not contain CDE, and are therefore believed not to be vulnerable:

• SCO UnixWare 2.1
• SCO OpenServer 5
• SCO Open Server 3.0
• SCO CMW+

SCO will provide further information and patches if necessary as soon as possible at http://www.sco.com/security.

IRIX does not have dtcm or rpc.cmsd and therefore is NOT vulnerable.

UNICOS does not have dtcm or rpc.cmsd and therefore is NOT vulnerable.

The following patches are available:

OpenWindows:

    SunOS version     Patch ID
    _____________     _________
    SunOS 5.5.1       104976-04
    SunOS 5.5.1_x86   105124-03
    SunOS 5.5         103251-09
    SunOS 5.5_x86     103273-07
    SunOS 5.3         101513-14
    SunOS 4.1.4       100523-25
    SunOS 4.1.3_U1    100523-25

CDE:

    CDE version       Patch ID
    ___________       ________
    1.3               107022-03
    1.3_x86           107023-03
    1.2               105566-07
    1.2_x86           105567-08

Patches for SunOS 5.4 and CDE 1.0.2 and 1.0.1 will be available within a week of the release of this advisory.

Sun security patches are available at:

http://sunsolve.sun.com/pub-cgi/show.pl?target=patches/patch-license&nav=pubpatches

The CERT Coordination Center would like to thank Chok Poh of Sun Microsystems, David Brumley of Stanford University, and Elias Levy of Security Focus for their assistance in preparing this advisory.

CERT/CC Contact Information

Email: cert@cert.org
Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
Postal address:

CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
U.S.A.

CERT/CC personnel answer the hotline 08:00-17:00 EST(GMT-5) / EDT(GMT-4) Monday through Friday; they are on call for emergencies during other hours, on U.S. holidays, and on weekends.

Using encryption

We strongly urge you to encrypt sensitive information sent by email. Our public PGP key is available from

http://www.cert.org/CERT_PGP.key

If you prefer to use DES, please call the CERT hotline for more information.

Getting security information

CERT publications and other security information are available from our web site

http://www.cert.org/

* "CERT" and "CERT Coordination Center" are registered in the U.S. Patent and Trademark Office.

NO WARRANTY
Any material furnished by Carnegie Mellon University and the Software Engineering Institute is furnished on an "as is" basis. Carnegie Mellon University makes no warranties of any kind, either expressed or implied as to any matter including, but not limited to, warranty of fitness for a particular purpose or merchantability, exclusivity or results obtained from use of the material. Carnegie Mellon University does not make any warranty of any kind with respect to freedom from patent, trademark, or copyright infringement.

Copyright 1999 Carnegie Mellon University.

January 7, 2000  Updated HP vendor information
July 22, 1999  Added link to IN-99-04 in the "Impact" section
July 20, 1999  Updated the advisory title
July 16, 1999  Initial release