‘Webkit Detached Body Element Code Execution Vulnerability’

Summary

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple Safari WebKit.’

Credit:

‘The information has been provided by Rob King.
The original article can be found at: http://www.zerodayinitiative.com/advisories/ZDI-11-140/


Details

Vulnerable Systems:
 * 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 how the application manages a reference to an anonymous block located near a particular element within the document. When cloning this element, the application will duplicate a reference to the block and then later re-attach this element to the rendering tree. During this process the library will free the original rendering element. Subsequent access to the same element will then cause the library to use the freed object. This can be utilized to achieve code execution under the context of the application.

Workaround:
Webkit fix:
http://trac.webkit.org/changeset/67182

Disclosure Timeline:
2011-03-31 – Vulnerability reported to vendor
2011-04-19 – Coordinated public release of advisory’

Categories: UNIX