Known exploited · VMware
CVE-2023-20867: VMware Tools Authentication Bypass Vulnerability
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.
- Vendor
- VMware
- Product
- Tools
- Added to KEV
- June 23, 2023
- CISA due date
- July 14, 2023
- Ransomware use
- Unknown
- Weakness
- CWE-287: Improper Authentication
What CISA requires
Apply updates per vendor instructions.
Forensic triage
No
What to do now
- Find every instance of Tools you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before July 14, 2023 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.