(Pwn2Own) Apple OS X fontd Sandbox Escape Vulnerability

May 27th, 2016
ZDI-16-360 ZDI-CAN-3606

CVE ID

CVE-2016-1797

CVSS Score

4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected Vendors

Apple

Affected Products

OS X

Vulnerability Details


This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple OS X. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the sandbox policy for the fontd process. The issue lies in the failure to properly ensure the FontValidator binary is either excluded from the policy, or is also sandboxed. An attacker can leverage this in conjunction with other vulnerabilities to execute code outside the context of the Safari sandbox.

Additional Details

Apple has issued an update to correct this vulnerability. More details can be found at:
https://support.apple.com/en-us/HT206567

Disclosure Timeline

  • 2016-03-16 - Vulnerability reported to vendor
  • 2016-05-27 - Coordinated public release of advisory

Credit

lokihardt

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