Apple Webkit SVG First-Letter Style Remote Code Execution Vulnerability

August 5th, 2010
ZDI-10-142 ZDI-CAN-782

CVE ID

CVE-2010-1785

CVSS Score

10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Affected Vendors

Apple

Affected Products

WebKit

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple Safari's 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 the first-letter style in the context of an SVG text element. Upon applying the style to this element, the library will calculate the height for determining the overflow for an inline box. While traversing the elements for the height, the library will utilize data from a non-existent linebox. Successful exploitation will lead to code execution under the context of the application.

Additional Details

Apple has issued an update to correct this vulnerability. More details can be found at:
http://support.apple.com/kb/HT4276

Disclosure Timeline

  • 2010-06-01 - Vulnerability reported to vendor
  • 2010-08-05 - Coordinated public release of advisory

Credit

wushi of team509

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