TippingPoint Zero Day Initiative

Citrix Metaframe Presentation Server Print Provider Buffer Overflow Vulnerability

ZDI-07-006: January 24th, 2007


Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability 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 Citrix Presentation Server, Metaframe Presentation Server or MetaFrame XP. Authentication is not required to exploit this vulnerability.

The specific flaw exists in a print provider installed by the Presentation Server. The cpprov.dll library doesn't properly handle certain invalid calls to the EnumPrintersW() and OpenPrinter() functions. For example, passing a string of 130 or more characters in the first argument to the OpenPrinter() function results in a stack-based buffer overflow and can be leveraged to execute code in the context of the Spooler service, which runs as the privileged LocalSystem account.

Vendor Response

Citrix states:

Disclosure Timeline

    2006-10-02 - Vulnerability reported to vendor
    2007-01-24 - Coordinated public release of advisory


This vulnerability was discovered by: