TippingPoint Zero Day Initiative

(Pwn2Own) Apple macOS smbfs Out-Of-Bounds Access Privilege Escalation Vulnerability

ZDI-17-359: May 18th, 2017


CVSS Score

Affected Vendors

Affected Products


Vulnerability Details

This vulnerability allows local attackers to escalate privileges on vulnerable installations of Apple macOS. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the handling of smbfs. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this vulnerability to escalate privileges in the context of the kernel.

Vendor Response

Apple has issued an update to correct this vulnerability. More details can be found at:

Disclosure Timeline

    2017-03-17 - Vulnerability reported to vendor
    2017-05-18 - Coordinated public release of advisory


This vulnerability was discovered by:
    Chaitin Security Research Lab