CyberSecBulletin
CVE-2023-34058NVD status: Modified

VMware Tools: Improper Verification of Cryptographic Signature

CVE-2023-34058 is a high-severity improper verification of cryptographic signature vulnerability in VMware Tools, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected VMware Tools versions: 12.x.x; 11.x.x; 10.3.x. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.81% chance of exploitation within 30 days, higher than 58% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Tools to 12.3.5 or a later version.
  2. Read the advisory on vmware.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
VMware ToolsVMware Tools12.x.x; 11.x.x; 10.3.xNot stated
Open-vm-toolsopen-vm-tools11.0.0 through 12.3.0Not stated
DebianDebian Linux10.0; 11.0; 12.0Not stated
VMwareTools10.3.0 up to, but not including, 12.3.512.3.5
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
AdjacentThe attacker must be on the same local network segment.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.17.1HighCNA (vmware.com)
CVSS 3.17.5HighNVD

Official description

VMware Tools contains a SAML token signature bypass vulnerability. A malicious actor that has been granted Guest Operation Privileges https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-security/GUID-6A952214-0E5E-4CCF-9D2A-90948FF643EC.html in a target virtual machine may be able to elevate their privileges if that target virtual machine has been assigned a more privileged Guest Alias https://vdc-download.vmware.com/vmwb-repository/dcr-public/d1902b0e-d479-46bf-8ac9-cee0e31e8ec0/07ce8dbd-db48-4261-9b8f-c6d3ad8ba472/vim.vm.guest.AliasManager.html .

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

The underlying weakness: Improper Verification of Cryptographic Signature

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

More Improper Verification of Cryptographic Signature vulnerabilities (CWE-347)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Other vulnerabilities in VMware Tools

All VMware Tools vulnerabilities

Recent Improper Verification of Cryptographic Signature vulnerabilities

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