1. Cleus
  2. Zero-days
  3. CVE-2023-20867
Exploited in the wildServers & business softwareWork IT

CVE-2023-20867 VMware Tools: login or permission bypass

In plain words: A door that should be locked is not: part of the system can be reached without a valid login or permission. The attacker gets in as a user or administrator without knowing a password.

Confirmed exploited by CISA on · US federal patch deadline Jul 14, 2023

What to do

  1. Install VMware's security update for Tools. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Keep a list of every internet-facing server you run so nothing is forgotten.
  3. Patch anything in this catalog first, ahead of normal patch cycles.
  4. Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.

Read VMware's advisory ↗

Who is affected

Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.

The details

Official name
VMware Tools Authentication Bypass Vulnerability
Product
VMware Tools
CISA description
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.
Type of flaw
Login or permission bypass (CWE-287)
Confirmed exploited
Jun 23, 2023
US federal patch deadline
Jul 14, 2023

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Answering about CVE-2023-20867 ·

Questions about CVE-2023-20867

Is CVE-2023-20867 being exploited?

Yes. CISA added CVE-2023-20867 to its Known Exploited Vulnerabilities catalog on Jun 23, 2023, which means there is reliable evidence of real-world attacks.

How do I fix CVE-2023-20867?

Install VMware's security update for Tools. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.

Am I affected by CVE-2023-20867?

Only if you use VMware Tools. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

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