TippingPoint Zero Day Initiative

Apple Safari JSString Out-Of-Bounds Access Remote Code Execution Vulnerability

ZDI-17-823: September 26th, 2017


CVSS Score

Affected Vendors

Affected Products

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 JSString objects. By performing actions in JavaScript, an attacker can trigger a memory access past the end of an allocated object. An attacker can leverage this vulnerability to execute code under the context of the current process.

Vendor Response

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

Disclosure Timeline

    2017-05-06 - Vulnerability reported to vendor
    2017-09-26 - Coordinated public release of advisory


This vulnerability was discovered by:
    Wang Junjie
    Wei Lei and Liu Yang of Nanyang Technological University