// For flags

CVE-2020-9939

Apple macOS kextload Time-Of-Check Time-Of-Use Memory Corruption Vulnerability

Severity Score

6.4
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

This issue was addressed with improved checks. This issue is fixed in macOS Catalina 10.15.6. A local user may be able to load unsigned kernel extensions.

Este problema fue abordado con comprobaciones mejoradas. Este problema se corrigió en macOS Catalina versión 10.15.6. Un usuario local puede ser capaz de cargar extensiones de kernel sin firmar

This vulnerability allows local attackers to escalate privileges on affected installations of Apple macOS. An attacker must first obtain the ability to execute high-privileged code on the target system in order to exploit this vulnerability.
The specific flaw exists within the handling of kernel extensions in kextload. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this in conjunction with other vulnerabilities to escalate privileges and execute code in the context of the kernel.

*Credits: @SSLab_Gatech (@jinmo123, @setuid0x0_, and @insu_yun_en)
CVSS Scores
Attack Vector
Local
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-03-02 CVE Reserved
  • 2020-08-10 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
CAPEC
References (1)
URL Tag Source
URL Date SRC
URL Date SRC
URL Date SRC
https://support.apple.com/kb/HT211289 2020-10-29
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Apple
Search vendor "Apple"
 Mac Os X
Search vendor "Apple" for product "Mac Os X"
 < 10.15.6
Search vendor "Apple" for product "Mac Os X" and version " < 10.15.6"
-
Affected