CyberSecBulletin
CVE-2023-20867Exploited in the wildNVD status: Analyzed

VMware Tools Authentication Bypass

Published Updated By the CyberSecBulletin desk

CVE-2023-20867 is a low-severity improper authentication vulnerability in VMware Tools from VMware, with a CVSS 3.1 base score of 3.9 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. CISA added it to the Known Exploited Vulnerabilities catalogue on June 23, 2023, which means attacks have been observed in the wild.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Tools to 12.2.5 or a later version.
  2. CISA's required action: Apply updates per vendor instructions.
  3. Read the advisory on vmware.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
VMwareVMware ToolsNot specified in the recordNot stated
VMwareTools10.3.0 up to, but not including, 12.2.512.2.5
DebianDebian Linux10.0; 11.0; 12.0Not stated
Fedora ProjectFedora37; 38; 39Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
LowSome restricted data can be read.
Integrity
LowLimited modification of data is possible.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.13.9LowCNA (vmware.com)
CVSS 3.13.9LowNVD

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

How developers prevent this class of flaw

  • Use an authentication framework or library such as the OWASP ESAPI Authentication feature.

More Improper Authentication vulnerabilities (CWE-287)

Timeline

  1. CVE record published.
  2. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: partial).
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in VMware Tools

All VMware Tools vulnerabilities

Recent Improper Authentication vulnerabilities

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