Advisory Details

February 24th, 2021

Apple macOS process_token_BlitLibSetup2D Time-Of-Check Time-Of-Use Privilege Escalation Vulnerability

ZDI-21-201
ZDI-CAN-11438

CVE ID CVE-2021-1806
CVSS SCORE 7.8, AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
AFFECTED VENDORS Apple
AFFECTED PRODUCTS macOS
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on affected 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 AppleIntelKBLGraphics kext. 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 in the context of the kernel.
ADDITIONAL DETAILS Apple has issued an update to correct this vulnerability. More details can be found at:
https://support.apple.com/HT212177
DISCLOSURE TIMELINE
  • 2020-09-02 - Vulnerability reported to vendor
  • 2021-02-24 - Coordinated public release of advisory
CREDIT ABC Research s.r.o.
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