Networksecurity.fi Security Advisory (21-12-2005)

Title: dtSearch DUNZIP32.dll Buffer Overflow Vulnerability
Criticality: High (3/3)
Affected software: dtSearch versions prior than 7.20 Build 7136
Author: Juha-Matti Laurio
Date: 21th December, 2005
Advisory ID: Networksecurity.fi Security Advisory (21-12-2005) (#15)
CVE reference: CVE-2004-1094

- From the vendor:
"Instantly Search Terabytes of Text
The dtSearch product line can instantly search terabytes of text across 
a desktop, network, Internet or Intranet site."

- Description:
dtSearch document search system is confirmed as affected to remote type 
buffer overflow vulnerability.
The vulnerability is caused due to a boundary error in a 3rd-party 
compression library's (DUNZIP32.dll) remarkable old, vulnerable version 
used when handling packed .ZIP documents. InnerMedia DynaZip compression 
library mentioned is responsible for indexing and displaying operations. 
This can be exploited to cause a buffer overflow via a specially crafted 
zipped document. When a specially crafted .zip document containing a 
file with an overly long filename (a file name or files inside a ZIP) is 
opened, the application will crash and the attacker may be able to 
execute arbitrary code on user's system (see US-CERT VU#582498 
reference).

- Detailed description:
Affected DynaZip library examined is version from December, 2002, file 
version 5.0.0.2. According to InnerMedia company versions 5.00.03 and 
prior are affected.
The following remarkable old file was copied to C:\Program 
Files\dtSearch\bin directory during an installation process when tested:
File name: dunzip32.dll
Date stamp: 6th December, 2002 04:05PM
File version: 5.0.0.2
Description: DynaZIP-32 Multi-Threading UnZIP DLL

NOTE: Dunzip32.dll is being installed into the same directory as the 
application executable of dtSearch Engine if dtSearch has been installed 
on end-users' machines. If the situation is as described, updating of 
the libary on end-users' machines by applying a software update is also 
needed.

>>From US-CERT VU#582498:
"Impact:
If a remote attacker can persuade a user to access a specially crafted 
zip file, the attacker may be able to execute arbitrary code on that 
user's system possibly with elevated privileges."

- Affected versions:
The vulnerability has been confirmed in dtSearch Desktop with Spider 
version 7.10 (Build 7045). Other versions may also be affected.
The newest dtSearch version from 6.x product line is dtSearch 6.5 Build 6608.
All earlier versions (vendor's Web pages list versions 1.x to 5.25) are 
probably affected as well.

- OS:
Microsoft Windows (Win 95/98/ME/NT/2000/XP/2003/.NET)
Tests was done with Microsoft Windows XP Professional SP2 and Microsoft 
Windows 2000 Professional SP4 fully patched.

- Solution status:
Vendor has issued a patch shipped with immune library version 5.00.07. 
It can be obtained by downloading a patch from:
http://www.dtsearch.com/download.html#upgrades

- Software:
dtSearch 7.x
dtSearch 6.x
http://www.dtsearch.com/PLF_desktop.html (Desktop with Spider)

Vendor and vendor Home Page:
dtSearch Corp.
http://www.dtsearch.com

Vendor product Web page:
http://www.dtsearch.com/PLF_desktop.html (Desktop with Spider)

- Solution:
Apply a patch 7.20 Build 7136 (version number 7.20.7136.1):
http://www.dtsearch.com/download.html#upgrades

- CVE information:
The Common Vulnerabilities and Exposures (CVE) project has assigned the 
name CVE-2004-1094 on 20th December, 2005 to this issue. This is a 
candidate for inclusion in the CVE list (http://cve.mitre.org ), which 
standardizes names for security problems.
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-1094
The CVSS (Common Vulnerability Scoring System) severity level metric of 
issue CVE-2004-1094: 10 (High)

- References:
US-CERT VU#582498:
"InnerMedia DynaZip library vulnerable to buffer overflow via long file names"
http://www.kb.cert.org/vuls/id/582498
>>From the vulnerability note:
"Users are encouraged to contact their software vendors if they suspect 
they are vulnerable."
Upgrade information for version 6.x or earlier:
http://support.dtsearch.com/faq/dts0201.htm

Credit information:
This vulnerability was researched by Juha-Matti Laurio, 
Networksecurity.fi (Finland).

Timeline:
12-Oct-2005 - Vulnerability researched and confirmed
05-Nov-2005 - Vendor was contacted
05-Nov-2005 - Vendor's reply, vendor informed about upcoming, fixed 
version and timeline
06-Nov-2005 - Vendor issues a patch, detailed research
20-Dec-2005 - CVE information submission sent to Mitre.org
20-Dec-2005 - Mitre.org assigns CVE-2004-1094
21-Dec-2005 - Security companies and several CERT units contacted
23-Dec-2005 - Public disclosure

A full version of security advisory is located at 
http://www.networksecurity.fi/advisories/dtsearch.html

Networksecurity.fi Weblog (Finnish language): 
http://networksecurity.typepad.com/