VMware Tools Authentication Bypass Vulnerability (CVE-2023-20867)

VMware Tools contains an authentication bypass vulnerability in the vgauth module. 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. An attacker must have root access over ESXi to exploit this vulnerability.

Published Jun 13, 2023 · Updated May 29, 2026

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Why patchRisk explained in plain English

Worst-case scenarioIf unpatched

A local attacker, with administrative privileges, can achieve full data confidentiality loss, partial data tampering. Federal agencies are required to remediate by 2023-07-14 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Improper Authentication (CWE-287) vulnerability in VMware Tools. 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. Exploitation requires local access, higher attack complexity, an administrative account, and no user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

●Virtualisation Administrators

●Infrastructure Team

●IT Security

●Running tools: 10.3.0 ≤ v < 12.2.5; debian linux: 10.0, 11.0, 12.0; fedora: 37, 38, 39

Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2023-06-23 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2023-07-14.

How to patch

Get the fix

Apply the fixed package from your vendor. The advisory lists affected versions and the exact fixed build.

↗ VMware advisory

Manual remediation steps