Advisory Details

October 30th, 2018

Apple macOS mDNSOffloadUserClient Race Condition Privilege Escalation Vulnerability

ZDI-18-1328
ZDI-CAN-6821

CVE ID CVE-2018-4326
CVSS SCORE 6.9, AV:L/AC:M/Au:N/C:C/I:C/A:C
AFFECTED VENDORS Apple
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 handling of the mDNSOffloadUserClient IOkit user client. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to escalate privileges and execute code as the kernel.
ADDITIONAL DETAILS Apple has issued an update to correct this vulnerability. More details can be found at:
https://support.apple.com/kb/HT201222
DISCLOSURE TIMELINE
  • 2018-07-24 - Vulnerability reported to vendor
  • 2018-10-30 - Coordinated public release of advisory
  • 2018-10-30 - Advisory Updated
CREDIT Anonymous
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