ZDI-10-243: Novell GroupWise Internet Agent TZNAME Parsing Remote Code Execution Vulnerability

http://www.zerodayinitiative.com/advisories/ZDI-10-243

November 8, 2010

-- CVSS:
10, (AV:N/AC:L/Au:N/C:C/I:C/A:C)

-- Affected Vendors:
Novell

-- Affected Products:
Novell Groupwise

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability by Digital Vaccine protection filter ID 10651.
For further product information on the TippingPoint IPS, visit:

    http://www.tippingpoint.com

-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of Novell GroupWise. Authentication is not
required to exploit this vulnerability.

The specific flaw exists within the gwwww1.dll module responsible for
parsing VCALENDAR data within e-mail messages. When the code encounters
a TZNAME variable it allocates up to 0xFFFF bytes for the variable's
value. It then proceeds to copy the value into the fixed-length buffer
without checking if it will fit. By specifying a large enough string in
the e-mail, an attacker can overflow the buffer and execute arbitrary
code under the context of the SYSTEM user.

-- Vendor Response:
Novell states:
Linux - http://download.novell.com/Download?buildid=04oMMaiI9nI~
NetWare/Windows -
http://download.novell.com/Download?buildid=aq06Eoy7rf4~

The GroupWise Internet Agent (GWIA) has multiple vulnerabilities in the
way that it parses variables within a received VCALENDAR message, which
could potentially allow an unauthenticated remote attacker to execute
arbitrary code on vulnerable installations of GWIA.
Affected versions: GroupWise 8.0x, 8.01x, 8.02. Previous versions of
GroupWise are likely also vulnerable but are no longer supported.
Customers on earlier versions of GroupWise should, at a minimum, upgrade
their GWIAs and associated Domains to version 8.02HP in order to secure
their system.
These vulnerabilities were discovered and reported by Anonymous working
with TippingPoint's Zero Day Initiative
(http://www.zerodayinitiative.com), ZDI-CAN-954,ZDI-CAN-960, ZDI-CAN-961

Novell bugs 642339, 642345, 642349, CVE numbers pending
Related TID:
http://www.novell.com/support/search.do?usemicrosite=true&searchString=7007155

-- Disclosure Timeline:
2010-09-24 - Vulnerability reported to vendor
2010-11-08 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by:
    * Anonymous

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