Time-of-check Time-of-use (TOCTOU) in VMware Fusion, VMRC for Mac and Horizon Client for Mac



Published: 2020-05-29
Risk Low
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2020-3957
CWE ID N/A
Exploitation vector Local
Public exploit N/A
Vulnerable software
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VMware Fusion
Client/Desktop applications / Virtualization software

VMRC
Client/Desktop applications / Software for system administration

VMware Horizon Client
Client/Desktop applications / Software for system administration

Vendor VMware, Inc

Security Advisory

This security advisory describes one low risk vulnerability.

1) Time-of-check Time-of-use (TOCTOU) Race Condition

Risk: Low

CVSSv3: 6.4 [CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2020-3957

CWE-ID: -

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a Time-of-check Time-of-use (TOCTOU) issue in the service opener. An local user can gain elevated privileges on the target system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

VMware Fusion: 11.0.0, 11.0.1, 11.0.2, 11.0.3, 11.1.0, 11.1.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3

VMRC: 8.0.0, 8.0.1, 8.1.0, 9.0.0, 10.0.0, 10.0.1, 10.0.2, 10.0.3, 10.0.4, 10.0.5, 10.0.6, 11.0.0, 11.0.1, 11.1.0

VMware Horizon Client: 3.0.0, 4.0.0, 4.1, 4.1.0, 4.2, 4.2.0, 4.3, 4.3.0, 4.4, 4.4.0, 4.5, 4.5.0, 4.6, 4.6.0, 4.7, 4.7.0, 4.8, 4.8.0, 4.9, 4.9.0, 4.10, 4.10.0, 5.0, 5.0.0, 5.1, 5.1.0, 5.2, 5.2.0, 5.3, 5.4

CPE External links

http://www.vmware.com/security/advisories/VMSA-2020-0011.html

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to open a a specially crafted file.

The attacker would have to login to the system and perform certain actions in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.