ZDI-10-239: Novell GroupWise Internet Agent RRULE Parsing Remote Code Execution Vulnerability

http://www.zerodayinitiative.com/advisories/ZDI-10-239

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 10650.
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 RRULE variable it allocates memory for 0x800 bytes for the variable's
contents, a list of numbers. It then proceeds to copy the numbers from
the request while there are numbers to parse. By specifying a large
amount of comma-separated values within an RRULE, 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

-- About the Zero Day Initiative (ZDI):
Established by TippingPoint, The Zero Day Initiative (ZDI) represents
a best-of-breed model for rewarding security researchers for responsibly
disclosing discovered vulnerabilities.

Researchers interested in getting paid for their security research
through the ZDI can find more information and sign-up at:

    http://www.zerodayinitiative.com

The ZDI is unique in how the acquired vulnerability information is
used. TippingPoint does not re-sell the vulnerability details or any
exploit code. Instead, upon notifying the affected product vendor,
TippingPoint provides its customers with zero day protection through
its intrusion prevention technology. Explicit details regarding the
specifics of the vulnerability are not exposed to any parties until
an official vendor patch is publicly available. Furthermore, with the
altruistic aim of helping to secure a broader user base, TippingPoint
provides this vulnerability information confidentially to security
vendors (including competitors) who have a vulnerability protection or
mitigation product.

Our vulnerability disclosure policy is available online at:

    http://www.zerodayinitiative.com/advisories/disclosure_policy/

Follow the ZDI on Twitter:

    http://twitter.com/thezdi