Apple macOS nsurlstoraged Integer Overflow Privilege Escalation Vulnerability

2017-11-20T00:00:00
ID ZDI-17-925
Type zdi
Reporter Niklas Baumstark and Samuel Gro
Modified 2017-11-21T00:00:00

Description

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.