Attacker Value
High
(1 user assessed)
Exploitability
Very High
(1 user assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
0

CVE-2020-3950

Disclosure Date: March 17, 2020
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

VMware Fusion (11.x before 11.5.2), VMware Remote Console for Mac (11.x and prior before 11.0.1) and Horizon Client for Mac (5.x and prior before 5.4.0) contain a privilege escalation vulnerability due to improper use of setuid binaries. Successful exploitation of this issue may allow attackers with normal user privileges to escalate their privileges to root on the system where Fusion, VMRC or Horizon Client is installed.

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2
Ratings
Technical Analysis

This vulnerability is trivial to exploit.
The “Open VMware USB Arbitrator Service” binary can be run (through a hard link) from any location, including attacker controlled. Next, when the Service binary is run, which any user can do, it automatically runs ../../../Contents/Library/services/VMware USB Arbitrator Service. By ensuring the hard link is 3 levels deep from VMware USB Arbitrator Service, we’re able to get code execution. When our payload (VMware USB Arbitrator Service) is run, it’s done so with an EUID of 0, thus priv escalating. This is trivial to exploit since we’re not overwriting any files, or calling anything abnormal, and easy to clean-up. There is NO chance of crashing the system either.

CVSS V3 Severity and Metrics
Base Score:
7.8 High
Impact Score:
5.9
Exploitability Score:
1.8
Vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Products

  • VMware Fusion, VMware Remote Console for Mac and Horizon Client for Mac

Additional Info

Technical Analysis