(Pwn2Own) Apple Safari ArrayStorage DFG Optimization Use-After-Free Remote Code Execution Vulnerability

May 19th, 2016
ZDI-16-343 ZDI-CAN-3619

CVE ID

CVE-2016-1857

CVSS Score

6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected Vendors

Apple

Affected Products

Safari

Vulnerability Details


This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple Safari. 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 handling of ArrayBuffer objects. By triggering certain JavaScript optimizations, an attacker can force an ArrayBuffer in memory to be reused after it has been freed. An attacker can leverage this vulnerability to execute code under the context of the current process.

Additional Details

Apple has issued an update to correct this vulnerability. More details can be found at:
https://support.apple.com/en-us/HT206568

Disclosure Timeline

  • 2016-03-16 - Vulnerability reported to vendor
  • 2016-05-19 - Coordinated public release of advisory

Credit

Liang Chen of KeenLab Tencent
Zhen Feng of KeenLab Tencent
wushi of KeenLab Tencent

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