Public Vulnerability Reports

Multiple Vendor OpenOffice QPRO File Parsing Integer Underflow Vulnerability



OpenOffice is an open-source desktop office suite for many of today's popular operating systems. One of the file formats that OpenOffice supports is Quattro Pro (QPRO). This format is used by Corel's QuattroPro spreadsheet application. More information is available from the following URL.


Remote exploitation of an integer underflow vulnerability in OpenOffice, as included in various vendors' operating system distributions, allows attackers to execute arbitrary code with the privileges of the logged in user.

The vulnerability exists within the code responsible for converting the QPRO file into an internal representation used by OpenOffice. A 16-bit integer is read in from the file, and later used as a loop counter that controls how many values are stored into local stack buffers. When verifying the value of this counter, the code decrements the counter without checking to see if this operation will underflow. This results in the loop running for many iterations, which leads to a stack based buffer overflow. This allows for the execution of arbitrary code.


Exploitation of this vulnerability results in the execution of arbitrary code with the privileges of the user opening the file. In order to exploit this vulnerability, an attacker must persuade a user to open a malicious file.


iDefense has confirmed the existence of this vulnerability in OpenOffice version 2.3. Other versions may also be affected.


Renaming the shared library that contains the vulnerable code will prevent OpenOffice from opening QPRO files. On Fedora Core 7, the library can be found at:


Renaming this file to will prevent it from being loaded. In addition to preventing the use of QPRO files, this also prevents users from opening various other file formats.


The team has addressed this vulnerability with the release of version 2.4. For more information, consult the OOo Security Bulletin at the following URL.


The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-5747 to this issue. This is a candidate for inclusion in the CVE list (, which standardizes names for security problems.


10/29/2007 Initial vendor notification
10/30/2007 Initial vendor response
04/17/2008 Coordinated public disclosure


The discoverer of this vulnerability wishes to remain anonymous.

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Copyright © 2008 Verisign, Inc.

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