INFORMATION BULLETIN
INFORMATION BULLETIN
| PROBLEM: | A vulnerability exists in Adobe Reader 5.1 when parsing an XFDF document. XFDF is a format for representing forms data and annotations in a PDF document. XFDF files have a .xfdf extension and are rendered automatically on downloading when using applications such as Internet Explorer. |
| SOFTWARE: | Adobe Reader 5.1 (on Windows platforms only) |
| DAMAGE: | Parsing the xfdf file causes an unsafe call to sprintf which then prepares for an output debug message using OutputDebugString. A buffer overflow occurs when rendering the xfdf file. A user would need to be enticed to a web site that hosts a malicious xfdf file or sent one via email. |
| SOLUTION: | Upgrade to the current version. |
| VULNERABILITY ASSESSMENT: |
The risk is MEDIUM. A buffer overflow occurs. This software is a widely used application. |
| LINKS: | |
| CIAC BULLETIN: | http://www.ciac.org/ciac/bulletins/o-091.shtml |
| ORIGINAL BULLETIN: | http://www.nextgenss.com/advisories/adobexfdf.txt |
[***** Start NGS Software Advisory number #NISR03022004 *****] [VulnWatch] Abobe Reader 5.1 XFDF Buffer Overflow Vulnerability From: NGSSoftware Insight Security Research (nisrnextgenss.com) Date: Wed Mar 03 2004 - 17:18:54 CST NGSSoftware Insight Security Research Advisory Name: Adobe Acrobat Reader XML Forms Data Format Buffer Overflow Systems Affected: Adobe Acrobat Reader version 5.1 Severity: High Risk Vendor URL: http://www.adobe.com/ Author: David Litchfield [ davidngssoftware.com ] Date Vendor Notified: 7th February 2004 Date of Public Advisory: 3rd March 2004 Advisory number: #NISR03022004 Advisory URL: http://www.nextgenss.com/advisories/adobexfdf.txt Description *********** Adobe Acrobat Reader is a viewer that renders PDF documents. The Reader can be extended using the XML Forms Data Format or XFDF. XFDF is a format for representing forms data and annotations in a PDF document. XFDF files have a .xfdf extention and are rendered automatically on downloaded when using applications such as Internet Explorer. Also note that, regardless of the file extention if the MIME type is set to "application/vnd.adobe.xfdf" the file will be treated as a XFDF. When parsing an XFDF document the Adobe Reader suffers from a classic stack based buffer overflow vulnerability. Details ******* When the xfdf file is parsed an unsafe call to sprintf is made in preparation for outputting a debug message using OutputDebugString. Whether the process is being debugged or not the vulnerable code is still called. Rendering the file will tigger the overflow. A user would need to be enticed to a web site that hosted a malicious xfdf file or sent one via e-mail. Fix Information *************** On contacting Adobe, they confirmed that the current version is no longer vulnerable and NGSSoftware urgently advises users of Adobe Reader to upgrade. http://www.adobe.com/support/downloads/main.html About NGSSoftware ***************** NGSSoftware design, research and develop intelligent, advanced application security assessment scanners. Based in the United Kingdom, NGSSoftware have offices in the South of London and the East Coast of Scotland. NGSSoftware's sister company NGSConsulting, offers best of breed security consulting services, specialising in application, host and network security assessments. http://www.ngssoftware.com/ Telephone +44 208 401 0070 Fax +44 208 401 0076 enquiriesngssoftware.com [***** End NGS Software Advisory number #NISR03022004 *****]
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