CVE-2021-2127

Hypervisor hang or repeated crash

Published Jan 20, 2021 · Updated Sep 26, 2024

Denial of service in Oracle VM VirtualBox Core before 6.1.18 allows local users to hang or repeatedly crash the hypervisor. Oracle's public advisory identifies only Core and does not disclose the flawed function, operation, or triggering input. Exploitation requires a high-privileged user logged on to the host infrastructure, and the bounded consequence is a hang or repeatedly reproducible crash.

CVSS severity4.4
Medium
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Oracle VM VirtualBox Core before 6.1.18 allows local users to hang or repeatedly crash the hypervisor. Oracle's public advisory identifies only Core and does not disclose the flawed function, operation, or triggering input. Exploitation requires a high-privileged user logged on to the host infrastructure, and the bounded consequence is a hang or repeatedly reproducible crash.

The record

CVE
CVE-2021-2127
Published
Jan 20, 2021
Updated
Sep 26, 2024
Vendor
Oracle Corporation
Product
Oracle VM VirtualBox
Classifications
T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jan 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 26, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <6.1.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Oracle Corporation · Oracle VM VirtualBoxversion=unspecified <6.1.18

Published CVSS scores

4.9NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:C
4.4OracleCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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