# VMware Tools: Authentication Bypass (CVE-2023-20867) · pwn.watch

> 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. Added to CISA KEV on 2023-06-23.

Page: https://pwn.watch/i/vmware-tools-cve-2023-20867 · generated 2026-10-23T03:01:01.167Z

## Status
- Severity: low · status: closed · patch: patched
- Product: VMware Tools
- Started: 2023-06-23 · closed: 2023-06-23
- CVEs: CVE-2023-20867
- Affected: See vendor advisory / CISA notes (versions not always listed in KEV feed)
- Fixed in: See vendor advisory linked in sources

## Follow this incident
- RSS (one item per update): https://pwn.watch/i/vmware-tools-cve-2023-20867/feed.xml
- JSON Feed: https://pwn.watch/i/vmware-tools-cve-2023-20867/feed.json
- Full data (timeline, sources, posts, agentBrief): https://pwn.watch/i/vmware-tools-cve-2023-20867.json
- This file: https://pwn.watch/i/vmware-tools-cve-2023-20867/llms.txt

## Updates (newest first)
- 2023-06-23: CISA added CVE-2023-20867 to the KEV catalog (due 2023-07-14).

## Fix brief
# Security brief: VMware Tools: Authentication Bypass (CVE-2023-20867)

Source: https://pwn.watch/i/vmware-tools-cve-2023-20867 · status: closed (closed Jun 23, 2023) · severity: low · updated Jun 23, 2023

## Patch status
**PATCHED: fixed releases exist. Upgrade to a fixed version.**

## What it is
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. Added to CISA KEV on 2023-06-23.

Severity detail: CVSS 3.9 (NVD), actively exploited (CISA KEV)

- Product: VMware Tools
- CVE / advisory ids: CVE-2023-20867

## Affected versions
- See vendor advisory / CISA notes (versions not always listed in KEV feed)

## Check whether you're affected
No generic command applies (the product is a hosted service, appliance or desktop app). Check the installed version in its admin UI / About screen and compare with the versions above.

## Fix
Upgrade to one of these fixed versions (or later on the same branch):
- See vendor advisory linked in sources

After upgrading, re-run the checks above and redeploy/restart the affected services.

## Latest updates
- Jun 23, 2023: CISA added CVE-2023-20867 to the KEV catalog (due 2023-07-14).

## Advisories
- [Vendor advisory: VMware Tools](https://www.vmware.com/security/advisories/VMSA-2023-0013.html) (VMware)
- [NVD: CVE-2023-20867](https://nvd.nist.gov/vuln/detail/CVE-2023-20867) (NVD)
- [CISA Known Exploited Vulnerabilities Catalog](https://www.cisa.gov/known-exploited-vulnerabilities-catalog) (CISA)

## Caveats
Derived from CISA KEV JSON feed catalogVersion 2026.10.21. Exact affected/fixed version strings are not always in the KEV record — verify against the vendor advisory URL. startedAt uses dateAdded (exploitation may have begun earlier).

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Machine-readable: https://pwn.watch/i/vmware-tools-cve-2023-20867.json · all incidents: https://pwn.watch/incidents.json. Verify against the vendor advisory before changing production systems.