ZDI-12-147 : WebKit ContentEditable swapInNode Use-After-Free Remote Code Execution Vulnerability

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ZDI-12-147 : WebKit ContentEditable swapInNode Use-After-Free Remote Code
Execution Vulnerability
http://www.zerodayinitiative.com/advisories/ZDI-12-147
August 22, 2012

• – CVE ID:
  CVE-2011-3897

• – CVSS:
  7.5, AV:N/AC:L/Au:N/C:P/I:P/A:P

• – Affected Vendors:
  WebKit.Org

• – Affected Products:
  WebKit.Org WebKit

• – TippingPoint(TM) IPS Customer Protection:
  TippingPoint IPS customers have been protected against this
  vulnerability by Digital Vaccine protection filter ID 12492.
  For further product information on the TippingPoint IPS, visit:

  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:
  This vulnerability was discovered by:

• pa_kt / twitter.com/pa_kt

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