Background exploitation KEV catalog
CVE-2023-20867

VMware Tools Authentication Bypass Vulnerability

A fully compromised ESXi host can force VMware Tools to fail to authenticate host-to-guest operations, impacting the confidentiality and integrity of the guest virtual machine.

CheckOps priority index
3.8/10 Patch within 7 days
Severity3.9
Probability1.4
Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 13.6% higher than 96.5% of CVEs
CVSS 3.1 3.9 AV:L/AC:H/PR:H/UI:N/S:C/C:L/I:
Exploited for 1,229 days 23 Jun 2023
CISA due date 14 Jul 2023 for US federal agencies

Exploitation probability EPSS · FIRST

05010026 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

  • KEV catalog (CISA)23 Jun 2023
  • Exploited in EUVD (ENISA)23 Jun 2023
  • Used by ransomwareno
  • EPSS above 10 %13.6%
  • No account, over the networkno

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Affected products

Tools
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 13.6%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2025-22226VMware ESXi, Workstation, and Fusion Information Disclosure Vulnerability
    4.1 · Background exploitation
  • CVE-2025-22225VMware ESXi Arbitrary Write Vulnerability
    5.1 · Background exploitation
  • CVE-2025-22224VMware ESXi and Workstation TOCTOU Race Condition Vulnerability
    5.0 · Background exploitation
  • CVE-2024-38813VMware vCenter Server Privilege Escalation Vulnerability
    5.3 · Background exploitation
  • CVE-2024-38812VMware vCenter Server Heap-Based Buffer Overflow Vulnerability
    8.0 · Background exploitation
  • CVE-2024-37085VMware ESXi Authentication Bypass Vulnerability
    5.9 · Background exploitation

Are you affected?

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities