---
id: "CVE-2023-20867"
kind: "vulnerability"
aliases: ["CVE-2023-20867"]
title: "A fully compromised ESXi host can force VMware Tools to fail to authenticate host-to-guest operations, impacting the\u2026"
severity: "high"
cvss: 3.9
epss: null
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "vmware tools", "fixed": ["12.2.5"], "affected": ">= 10.3.0, < 12.2.5", "ecosystem": "vendor"}, {"name": "debian linux", "fixed": [], "affected": "= 10.0", "ecosystem": "vendor"}, {"name": "debian linux", "fixed": [], "affected": "= 11.0", "ecosystem": "vendor"}, {"name": "debian linux", "fixed": [], "affected": "= 12.0", "ecosystem": "vendor"}, {"name": "fedoraproject fedora", "fixed": [], "affected": "= 37", "ecosystem": "vendor"}, {"name": "fedoraproject fedora", "fixed": [], "affected": "= 38", "ecosystem": "vendor"}, {"name": "fedoraproject fedora", "fixed": [], "affected": "= 39", "ecosystem": "vendor"}, {"name": "VMware Tools", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["esxi", "exploited", "infrastructure", "virtual-machines", "vmware-tools", "vsphere"]
not_affected_if: ["no-esxi-host-compromise", "vmware-tools-not-installed"]
published_at: "2023-06-13T17:15:14+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-24T00:09:51+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-20867", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-20867", "first_seen_at": "2026-10-23T22:29:04+00:00"}]
---

# A fully compromised ESXi host can force VMware Tools to fail to authenticate host-to-guest operations, impacting the…

VMware Tools has an authentication bypass in its vgauth module that lets host-to-guest operations skip authentication. An attacker who has fully compromised the ESXi host can read or change data inside the guest virtual machine.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:vmware tools affected >= 10.3.0, < 12.2.5 fixed 12.2.5
- vendor:debian linux affected = 10.0 fixed ?
- vendor:debian linux affected = 11.0 fixed ?
- vendor:debian linux affected = 12.0 fixed ?
- vendor:fedoraproject fedora affected = 37 fixed ?
- vendor:fedoraproject fedora affected = 38 fixed ?
- vendor:fedoraproject fedora affected = 39 fixed ?
- vendor:VMware Tools affected ? fixed ?

## Fix

Apply the VMware Tools update per vendor instructions; the fixed version is unknown from the sources.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-20867
- 2026-10-23T22:29:04+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2023-20867

## From the sources

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.

CISA required action: Apply updates per vendor instructions.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_