dbcve.org
EsxiOperating system · VMware

CVE-2019-5531

MEDIUM · 5.4 CVSS v3.1 Published 2019-09-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
61/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
VMware vSphere ESXi (6.7 prior to ESXi670-201810101-SG, 6.5 prior to ESXi650-201811102-SG, and 6.0 prior to ESXi600-201807103-SG) and VMware vCenter Server (6.7 prior to 6.7 U1b, 6.5 prior to 6.5 U2b, and 6.0 prior to 6.0 U3j) contain an information disclosure vulnerability in clients arising from insufficient session expiration. An attacker with physical access or an ability to mimic a websocket connection to a user’s browser may be able to obtain control of a VM Console after the user has logged out or their session has timed out.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

VMware vSphere ESXi and vCenter Server versions prior to the listed patches contain an information disclosure vulnerability where session tokens remain valid after user logout or session timeout. An attacker with physical access or the ability to mimic/hijack a websocket connection to a user's browser can obtain control of a VM Console session that should have been terminated.

MitigationUpgrade to the fixed versions: ESXi670-201810101-SG, ESXi650-201811102-SG, ESXi600-201807103-SG or later for ESXi; vCenter 6.7 U1b, 6.5 U2b, 6.0 U3j or later. Alternatively, enforce network-level controls to prevent physical access and websocket hijacking.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
EsxiOperating system
Affected:= 6.7
Vsphere EsxiOperating system
Affected:= 6.7= 6.5= 6.0
Vcenter ServerApplication
Affected:= 6.0= 6.7= 6.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify ESXi version
    Run 'vmware -l' on the ESXi host or check the host client Summary tab to find the build number
    Affected if Version is 6.0, 6.5, or 6.7 without the corresponding patch (ESXi670-201810101-SG, ESXi650-201811102-SG, or ESXi600-201807103-SG)
  2. Identify vCenter Server version
    Log into vSphere Web Client, go to Administration > System Configuration > vCenter Server > About, or run 'vmdir --action adhoc --uri 'http://localhost/sso/admin/about' on the vCenter appliance
    Affected if Version is 6.0, 6.5, or 6.7 without the corresponding patch (6.7 U1b, 6.5 U2b, or 6.0 U3j)
  3. Verify VM Console access is enabled
    Check that the VM Remote Console (VMRC) or Web Console is accessible by attempting to open a console to any managed VM, or verify the WebSocket proxy service is running with 'systemctl status vmware-websocket-server' on ESXi
    Affected if VM Console functionality is in use and the underlying ESXi/vCenter is a vulnerable version
  4. Confirm WebSocket endpoint exposure
    Check for open ports 443/TCP (HTTPS) and 8080/TCP (WebSocket) on the ESXi host or vCenter that accept console connections, or review firewall rules for WebSocket traffic
    Affected if WebSocket connections to VM Consoles are permitted and the environment runs a vulnerable ESXi/vCenter version

The environment is affected if either ESXi or vCenter Server is version 6.0, 6.5, or 6.7 without the respective security patches and VM Console sessions are accessible.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to the fixed versions: ESXi670-201810101-SG, ESXi650-201811102-SG, ESXi600-201807103-SG or later for ESXi; vCenter 6.7 U1b, 6.5 U2b, 6.0 U3j or later. Alternatively, enforce network-level controls to prevent physical access and websocket hijacking.

Fix this in Esxi Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-5531 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data