Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2008.0596 -- [Win][UNIX/Linux]
Multiple Vendor OpenOffice rtl_allocateMemory() Integer
Overflow Vulnerability
11 June 2008
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: OpenOffice 2.4
Publisher: iDEFENSE
Operating System: UNIX variants (UNIX, Linux, OSX)
Windows
Impact: Execute Arbitrary Code/Commands
Access: Remote/Unauthenticated
CVE Names: CVE-2008-2152
Original Bulletin: http://labs.idefense.com/intelligence/vulnerabilities/
- --------------------------BEGIN INCLUDED TEXT--------------------
iDefense Security Advisory 06.10.08
http://labs.idefense.com/intelligence/vulnerabilities/
Jun 10, 2008
I. BACKGROUND
OpenOffice is an open-source desktop office suite for many of today's
popular operating systems. For more information, see the vendor's site
found at the following URL.
http://www.openoffice.org/
II. DESCRIPTION
Remote exploitation of an integer overflow vulnerability in OpenOffice,
as included in various vendors' operating system distributions, allows
attackers to execute arbitrary code with the privileges of the
logged-in user.
The vulnerability exists due to the rtl_allocateMemory() function
rounding up allocation requests to be aligned on an 8 byte boundary
without checking if this rounding results in an integer overflow
condition. The vulnerable code is as follows, taken from
sal/rtl/source/alloc_global.c:
191 void *
192 SAL_CALL rtl_allocateMemory (sal_Size n)
193 {
194 void * p = 0;
195 if (n > 0)
196 {
197 char * addr;
198 sal_Size size = RTL_MEMORY_ALIGN(n +
RTL_MEMALIGN, RTL_MEMALIGN);
199
200 int index = (size - 1) >> RTL_MEMALIGN_SHIFT;
201 OSL_ASSERT(RTL_MEMALIGN >= sizeof(sal_Size));
202
203 try_alloc:
204 if (index < RTL_MEMORY_CACHED_LIMIT >>
RTL_MEMALIGN_SHIFT)
205 addr =
(char*)rtl_cache_alloc(g_alloc_table[index]);
206 else
207 addr = (char*)rtl_arena_alloc
(gp_alloc_arena, &size);
208
The problem occurs at line 198. The n + RTL_MEMALIGN calculation can
overflow if n > UINT_MAX - RTL_MEMALIGN. This results in an undersized
buffer being allocated at try_alloc. This buffer is then passed back to
the calling function, which assumes that the buffer is much larger than
it actually is. This results in a heap overflow.
As this vulnerability occurs in the core memory allocator, there are
numerous ways to trigger the vulnerable code using a wide variety of
different file types.
III. ANALYSIS
Exploitation of this vulnerability results in the execution of arbitrary
code with the privileges of the user opening the file. To exploit this
vulnerability, an attacker needs to convince a user to open a malicious
file. After opening the file, no further interaction is needed.
IV. DETECTION
iDefense has confirmed the existence of this vulnerability in OpenOffice
version 2.4. Previous versions may also be affected.
V. WORKAROUND
iDefense is currently unaware of any workarounds for this issue. Since
the vulnerability can be triggered by so many different file types,
disabling access to certain file types is not a valid workaround. As
such, avoid opening files from untrusted parties and unexpected files
from trusted parties.
VI. VENDOR RESPONSE
OpenOffice.Org has addressed this vulnerability by releasing version
2.4.1 of their product. For more information, consult the OOo Security
Bulletin at the following URL.
http://www.openoffice.org/security/cves/CVE-2008-2152.html
VII. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2008-2152 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for
security problems.
VIII. DISCLOSURE TIMELINE
05/08/2008 Initial vendor notification
05/09/2008 Initial vendor response
06/10/2008 Coordinated public disclosure
IX. CREDIT
This vulnerability was discovered by Sean Larsson, iDefense Labs.
Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php
Free tools, research and upcoming events
http://labs.idefense.com/
X. LEGAL NOTICES
Copyright © 2008 iDefense, Inc.
Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDefense. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically,
please e-mail customerservice@idefense.com for permission.
Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct,
indirect, or consequential loss or damage arising from use of, or
reliance on, this information.
_______________________________________________
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
http://www.auscert.org.au/render.html?cid=1980
If you believe that your computer system has been compromised or attacked in
any way, we encourage you to let us know by completing the secure National IT
Incident Reporting Form at:
http://www.auscert.org.au/render.html?it=3192
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
iQCVAwUBSE8xQih9+71yA2DNAQInWwP/VBMuzStJo9Aitf+hf6PyV2CqFL447zVf
a0h0KJnSuB5iXQmfnEu5D40tu5M5jOeuK9KvnJpbelyUzz5YmM+BKuxwOkEahjkP
afUM2Xakiq57CXnIZuXTQTTlCvn3Z7kR0LxeAE7e+vf/7tODWY9GBEe+o8wWdSAs
devpLIrDDn4=
=aL/R
-----END PGP SIGNATURE-----