Webkit HTMLMedia Element beforeLoad Remote Code Execution Vulnerability

December 21st, 2012
ZDI-12-191 ZDI-CAN-1528

CVE ID

CVE-2011-3071

CVSS Score

7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected Vendors

WebKit.Org

Affected Products

WebKit

Vulnerability Details


This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple Safari Webkit. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the library's implementation of a HTMLMedia element. After a source element is created, an attacker can catch the beforeLoad event before the element is used, and delete the element. The pointer to the source element will then be referenced causing a use-after-free condition, which can lead to code execution under the context of the application.

Additional Details

WebKit.Org has issued an update to correct this vulnerability. More details can be found at:
http://support.apple.com/kb/HT1222

Disclosure Timeline

  • 2012-03-14 - Vulnerability reported to vendor
  • 2012-12-21 - Coordinated public release of advisory

Credit

pa_kt / twitter.com/pa_kt

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