Advisory Details

August 22nd, 2012

WebKit ContentEditable swapInNode Use-After-Free Remote Code Execution Vulnerability

ZDI-12-147
ZDI-CAN-1416

CVE ID CVE-2011-3897
CVSS SCORE 7.5, (AV:N/AC:L/Au:N/C:P/I:P/A:P)
AFFECTED VENDORS WebKit.Org
AFFECTED PRODUCTS WebKit
TREND MICRO CUSTOMER PROTECTION Trend Micro TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 12492. For further product information on the TippingPoint IPS: http://www.tippingpoint.com
VULNERABILITY DETAILS


This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of the WebKit library. 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 when the library attempts to replace a particular element due to an HTML5 ContentEditable command. Due to the library not accommodating for DOM mutation events that can be made to occur, an aggressor can modify the tree out from underneath the library, leading to a type change. This can be used to trigger a use-after-free condition at which point can lead to code execution under the context of the application.

VENDOR RESPONSE WebKit.Org has issued an update to correct this vulnerability. More details can be found at:
https://bugs.webkit.org/show_bug.cgi?id=71145
DISCLOSURE TIMELINE
  • 2011-10-28 - Vulnerability reported to vendor
  • 2012-08-22 - Coordinated public release of advisory
CREDIT pa_kt / twitter.com/pa_kt
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