CyberSecBulletin
CVE-2025-41239NVD status: Deferred

ESXi: Use of Uninitialized Resource

Published Updated By the CyberSecBulletin desk

CVE-2025-41239 is a high-severity use of uninitialized resource vulnerability in ESXi from VMware, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists versions ESXi80U3f-24784735, ESXi80U2e-24789317, ESXi70U3w-24784741 as the first without the flaw, so updating ESXi to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 3.16% chance of exploitation within 30 days, higher than 88% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update ESXi to ESXi80U3f-24784735 or ESXi80U2e-24789317 or ESXi70U3w-24784741, whichever matches your release line, or a later version.
  2. Update Workstation to 17.6.4 or a later version.
  3. Update Fusion to 13.6.4 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
VMwareESXi8.0 up to, but not including, ESXi80U3f-24784735; 8.0 up to, but not including, ESXi80U2e-24789317; 7.0 up to, but not including, ESXi70U3w-24784741ESXi80U3f-24784735, ESXi80U2e-24789317, ESXi70U3w-24784741
VMwareCloud Foundation5.x, 4.5.xNot stated
VMwareWorkstation17.x up to, but not including, 17.6.417.6.4
VMwareFusion13.x up to, but not including, 13.6.413.6.4
VMwareTelco Cloud Platform5.x, 4.x, 3.x, 2.xNot stated
VMwareTelco Cloud Infrastructure3.x, 2.xNot stated
VMwareTools13.x.x up to, but not including, 13.0.1.0; 12.x.x, 11.x.x, up to, but not including, 12.5.313.0.1.0, 12.5.3

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
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N. Scored by CNA (vmware.com).

Official description

VMware ESXi, Workstation, Fusion, and VMware Tools contains an information disclosure vulnerability due to the usage of an uninitialised memory in vSockets. A malicious actor with local administrative privileges on a virtual machine may be able to exploit this issue to leak memory from processes communicating with vSockets.

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

The underlying weakness: Use of Uninitialized Resource

The product uses or accesses a resource that has not been initialized.

How developers prevent this class of flaw

  • Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
  • Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
  • Avoid race conditions (CWE-362) during initialization routines.

More Use of Uninitialized Resource vulnerabilities (CWE-908)

Timeline

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

References

Other vulnerabilities in ESXi

All ESXi vulnerabilities

Recent Use of Uninitialized Resource vulnerabilities

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