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CERT* Vendor-Initiated Bulletin VB-97.12
October 27, 1997
Topic: Potential denial of service attack in the OSF/DCE security server
Source: The Open Group
To aid in the wide distribution of essential security information, the CERT
Coordination Center is forwarding the following information from The Open
Group. Open Group urges you to act on this information as soon as
possible. Open Group contact information is included in the forwarded text
below; please contact them if you have any questions or need further
information.
=======================FORWARDED TEXT STARTS HERE============================
Advisory on OSF/DCE Denial of Service Attack
October 23, 1997
It has been discovered that OSF/DCE has a potential problem in the
security server that could allow for a denial of service attack.
PROBLEM:
If a principal, group, or organization is greater than 1024 characters
(including the cell name, so the actual name limit is less than 1024)
when passed to security daemon (secd), it will cause secd core dump.
The buffer is overrun causing memory corruption. In certain cases,
the lookup attempt (or add or whatever) on the client will then
rebind to another secd to make the request, eventually crashing
all security daemons in the cell.
HOW TO AVOID:
This potential denial of service attack has existed in all releases
of OSF/DCE to date. The Open Group sent a notification to all current
DCE support licensees providing the following fix. The Open Group is
in the process of incorporating a fix for this defect to all future DCE
maintenance releases. The end-users may ask their DCE vendors for
such a fix.
SOURCE CODE FIX:
The quick fix is the following:
In rsdb_name_util.c, the "rsdb_name_util_complete_name" routine
should perform the following check after the ustrncpy.
/* Retrieve the name_key record of the given domain directory. */
if(!check_domain(domain)) {
SET_STATUS(st, sec_rgy_bad_domain);
return false;
}
rsdb_util_get_key_of_id(domain, START_OF_LIST,
(Pointer)&name_key, &name_key_len);
ustrncpy(complete_name, name_key.name, name_key.name_len);
complete_name[name_key.name_len] = '\0';
#ifdef FIX
if (object_name_len < 1 ||
object_name_len + name_key.name_len + 1 > sec_rgy_name_t_size - 1)
{
return false;
}
#endif /* FIX */
if(object_name_len > 0) {
ustrcat(complete_name, "/");
ustrcat(complete_name, object_name);
}
return true;
CONTACT INFORMATION:
The Open Group DCE Systems Engineering
The Open Group
11 Cambridge Center,
Cambridge, MA 02142
Telephone: +1 617 621 8990
E-mail: dce-support-admin@opengroup.org
========================FORWARDED TEXT ENDS HERE=============================
If you believe that your system has been compromised, contact the CERT
Coordination Center or your representative in the Forum of Incident Response
and Security Teams (FIRST). See http://www.first.org/team-info/.
We strongly urge you to encrypt any sensitive information you send by email.
The CERT Coordination Center can support a shared DES key and PGP. Contact
the CERT staff for more information.
Location of CERT PGP key
ftp://ftp.cert.org/pub/CERT_PGP.key
CERT Contact Information
- ------------------------
Email cert@cert.org
Phone +1 412-268-7090 (24-hour hotline)
CERT personnel answer 8:30-5:00 p.m. EST
(GMT-5)/EDT(GMT-4), and are on call for
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Fax +1 412-268-6989
Postal address
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
USA
CERT publications, information about FIRST representatives, and other
security-related information are available from
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CERT advisories and bulletins are also posted on the USENET newsgroup
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This file: ftp://ftp.cert.org/pub/cert_bulletins/VB-97.12.opengroup
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