How severe is CVE-2020-3999?

CVE-2020-3999 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-3999 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3999?

CVE-2020-3999 primarily affects Vmware Workstation. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-3999?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-3999 published?

CVE-2020-3999 was published on 2020-12-21 and last updated on 2026-06-17.

CVE-2020-3999

CVE-2020-3999 is a medium-severity vulnerability in Vmware Workstation with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 2.1
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Vmware Workstation
Published: 2020-12-21
Last modified: 2026-06-17

Description

VMware ESXi (7.0 prior to ESXi70U1c-17325551), VMware Workstation (16.x prior to 16.0 and 15.x prior to 15.5.7), VMware Fusion (12.x prior to 12.0 and 11.x prior to 11.5.7) and VMware Cloud Foundation contain a denial of service vulnerability due to improper input validation in GuestInfo. A malicious actor with normal user privilege access to a virtual machine can crash the virtual machine's vmx process leading to a denial of service condition.

Frequently asked questions

What is CVE-2020-3999?: VMware ESXi (7.0 prior to ESXi70U1c-17325551), VMware Workstation (16.x prior to 16.0 and 15.x prior to 15.5.7), VMware Fusion (12.x prior to 12.0 and 11.x prior to 11.5.7) and VMware Cloud Foundation contain a denial of service vulnerability due to improper input validation in GuestInfo. A malicious actor with normal user privilege access to a virtual machine can crash the virtual machine's vmx process leading to a denial of service condition.
How severe is CVE-2020-3999?: CVE-2020-3999 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-3999 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3999?: CVE-2020-3999 primarily affects Vmware Workstation. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3999?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-3999 published?: CVE-2020-3999 was published on 2020-12-21 and last updated on 2026-06-17.

References

https://www.vmware.com/security/advisories/VMSA-2020-0029.html

Affected products (7)

cpe:2.3:a:vmware:workstation:*:*:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:7.0:-:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:7.0:beta:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:7.0:update_1:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:7.0:update_1a:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:7.0:update_1b:*:*:*:*:*:*
cpe:2.3:a:vmware:fusion:*:*:*:*:*:*:*:*

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