CVE-2021-2475

Privileged denial of service via core hang

Published Oct 20, 2021 · Updated Sep 25, 2024

A denial-of-service flaw in the Core component of Oracle Corporation Oracle VM VirtualBox before 6.1.28 allows local users to hang or crash the hypervisor. Oracle has not published the specific Core operation or input handling defect that triggers the failure. Exploitation requires high privileges and logon to the infrastructure hosting VirtualBox, with impact limited to a hang or repeatedly reproducible crash of the virtualization service.

CVSS severity4.4
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A denial-of-service flaw in the Core component of Oracle Corporation Oracle VM VirtualBox before 6.1.28 allows local users to hang or crash the hypervisor. Oracle has not published the specific Core operation or input handling defect that triggers the failure. Exploitation requires high privileges and logon to the infrastructure hosting VirtualBox, with impact limited to a hang or repeatedly reproducible crash of the virtualization service.

The record

CVE
CVE-2021-2475
Published
Oct 20, 2021
Updated
Sep 25, 2024
Vendor
Oracle Corporation
Product
Oracle VM VirtualBox
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 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 <6.1.28

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Oracle Corporation · Oracle VM VirtualBoxversion=unspecified <6.1.28

Published CVSS scores

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

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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