Public Vulnerability Reports

Opera Software Opera Web Browser JPG Image DHT Marker Heap Corruption Vulnerability



Opera is a cross-platform web browser. More information is available at


Remote exploitation of a heap overflow in Opera Software ASA's Opera Web browser could allow an attacker to execute arbitrary code in the security context of the current user.

The vulnerability specifically exists due to Opera improperly processing a JPEG DHT marker. The DHT marker is used to define a Huffman Table which is used for decoding the image data. An invalid number of index bytes in the DHT marker will trigger a heap overflow with partially user controlled data.


Exploitation of this vulnerability would allow an attacker to execute arbitrary code on the affected host. The attacker would first need to construct a website containing the malicious image and trick the vulnerable user into visiting the site. This would trigger the vulnerability and allow the code to execute with the privileges of the local user.


iDefense has confirmed the existence of this vulnerability in Opera version 9.02 on both Windows and Linux. Previous versions may also be affected.


iDefense is currently unaware of any effective workarounds for this issue.


Opera Software has addressed this vulnerability in version 9.10. More information is available at the following link.


A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not been assigned yet.


11/16/2006 Initial vendor notification
11/17/2006 Initial vendor response
01/05/2007 Coordinated public disclosure


This vulnerability was reported to iDefense by Christoph Diehl.

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Copyright © 2006 Verisign, Inc.

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