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Vm VirtualboxApplication · Oracle

CVE-2021-2126

MEDIUM · 6.0 CVSS v3.1 Published 2021-01-20
Fix available
A fix is available. Upgrade to 6.1.18 or later.
See remediation →
62/100
Remediation priority · Elevated
Zero-click

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
Vulnerability in the Oracle VM VirtualBox product of Oracle Virtualization (component: Core). The supported version that is affected is Prior to 6.1.18. Easily exploitable vulnerability allows high privileged attacker with logon to the infrastructure where Oracle VM VirtualBox executes to compromise Oracle VM VirtualBox. While the vulnerability is in Oracle VM VirtualBox, attacks may significantly impact additional products. Successful attacks of this vulnerability can result in unauthorized creation, deletion or modification access to critical data or all Oracle VM VirtualBox accessible data. CVSS 3.1 Base Score 6.0 (Integrity impacts). CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N).

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

This is a vulnerability in Oracle VM VirtualBox's Core component affecting versions prior to 6.1.18. A high-privileged attacker with local logon access can exploit this to achieve unauthorized creation, deletion, or modification of critical data. The scope change indicates the attack can impact additional products beyond VirtualBox itself. The vulnerability has high integrity impact but no confidentiality or availability impact.

MitigationUpgrade Oracle VM VirtualBox to version 6.1.18 or later. Since this requires high privileges to exploit, ensure proper access controls and least-privilege principles are applied to systems running VirtualBox.

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
Vm VirtualboxApplication
Affected:< 6.1.18

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
Local
Complexity
Low
Privileges
High
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:H/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. Verify VirtualBox is installed
    On Windows: Check for VirtualBox in Program Files\Oracle\VirtualBox or look for the VirtualBox application. On Linux: Run 'dpkg -l | grep virtualbox' or 'rpm -qa | grep virtualbox'. On macOS: Check /Applications for VirtualBox.app.
    Affected if VirtualBox is not installed on the system, the CVE does not apply.
  2. Determine installed VirtualBox version
    On Windows: Open Command Prompt and run 'vboxmanage --version' or check the VirtualBox GUI Help > About. On Linux/macOS: Run 'vboxmanage --version' in terminal.
    Affected if Unable to retrieve a version number indicates VirtualBox may not be properly installed.
  3. Compare version against vulnerable range
    Compare the installed version to 6.1.18. Versions prior to 6.1.18 are affected (e.g., 6.1.16, 6.1.14, 6.0.14, etc.).
    Affected if Installed version is less than 6.1.18 (e.g., 6.1.16, 6.0.14, 5.1.x) indicates the system is within the vulnerable version range.
  4. Assess local access privileges
    Identify accounts with high-privileged local logon access to the VirtualBox host system. Check for administrator, root, or equivalent accounts.
    Affected if The vulnerability requires high-privileged local access to exploit; if only standard user accounts exist with logon rights, the practical exploitability is reduced.

System is affected if VirtualBox version is installed and is less than 6.1.18, and an attacker could obtain high-privileged local logon access to the host.

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
Upgrade available Upgrade to 6.1.18 or later
Fixed in 6.1.18
Interim mitigation

Upgrade Oracle VM VirtualBox to version 6.1.18 or later. Since this requires high privileges to exploit, ensure proper access controls and least-privilege principles are applied to systems running VirtualBox.

Fix this in Vm Virtualbox Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.

Scan for this in your stack

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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-2021-2126 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