TippingPoint Zero Day Initiative
 

Apple macOS nsurlstoraged Integer Overflow Privilege Escalation Vulnerability

ZDI-17-925: November 20th, 2017

CVE ID

CVSS Score

Affected Vendors

Affected Products

    macOS

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 nsurlstoraged service. The issue results from the lack of proper validation of a reference count, which can result in an integer overflow when incrementing it. An attacker can leverage this vulnerability to escalate privileges under the context of the current service.

Vendor Response

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

Disclosure Timeline

    2017-06-22 - Vulnerability reported to vendor
    2017-11-20 - Coordinated public release of advisory

Credit

This vulnerability was discovered by:
    Niklas Baumstark and Samuel Gro