[Full-disclosure] ZDI-06-043: Novell Netware Client Print Provider Buffer Overflow Vulnerability
zdi-disclosures at 3com.com
zdi-disclosures at 3com.com
Wed Nov 29 17:10:37 GMT 2006
ZDI-06-043: Novell Netware Client Print Provider Buffer Overflow
November 29, 2006
-- CVE ID:
-- Affected Vendor:
-- Affected Products:
Novell Netware Client 4.91
Novell Netware Client 4.91 SP1
Novell Netware Client 4.91 SP2
-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability since July 7, 2005 by Digital Vaccine protection
filter ID 3583. For further product information on the TippingPoint IPS:
-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
systems with vulnerable installations of the Novell Netware Client.
Authentication is not required to exploit this vulnerability.
The specific flaw exists in a print provider installed by the Netware
Client. The nwspool.dll library does not properly handle long arguments
to the Win32 EnumPrinters() and OpenPrinter() functions. Exceeding 458
bytes in the first argument to OpenPrinter() or 524 bytes in the second
argument to EnumPrinters() results in an exploitable buffer overflow
within the Spooler service.
This vulnerability can be exploited remotely via Remote Procedure Call
(RPC) requests to the Spooler service. The Spooler exposes the
"spoolss" named pipe, which allows an anonymous user to issue certain
spooler commands. These include the OpenPrinter() and EnumPrinters()
calls required to exploit this vulnerability.
-- Vendor Response:
Novell has issued an update to correct this vulnerability. More details
can be found at:
-- Disclosure Timeline:
2005.07.07 - Digital Vaccine released to TippingPoint customers
2006.10.02 - Vulnerability reported to vendor
2006.11.29 - Coordinated public release of advisory
This vulnerability was discovered by an anonymous researcher.
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Instead, upon notifying the affected product vendor, 3Com provides its
customers with zero day protection through its intrusion prevention
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vulnerability are not exposed to any parties until an official vendor
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