CVE-2023-21991

Hypervisor data disclosure via VGA MMIO over-read

Published Apr 18, 2023 · Updated Sep 16, 2024

An out-of-bounds read in Oracle VM VirtualBox Core before 6.1.44 or 7.0.8 allows guest OS users to disclose hypervisor data via VGA MMIO. The VGA MMIO handler fails to validate guest-supplied data before reading an allocated buffer, permitting a read past its end. Exploitation requires high-privileged code execution in a guest and exposes only a subset of data accessible to the hypervisor.

CVSS severity3.2
Low
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds read in Oracle VM VirtualBox Core before 6.1.44 or 7.0.8 allows guest OS users to disclose hypervisor data via VGA MMIO. The VGA MMIO handler fails to validate guest-supplied data before reading an allocated buffer, permitting a read past its end. Exploitation requires high-privileged code execution in a guest and exposes only a subset of data accessible to the hypervisor.

The record

CVE
CVE-2023-21991
Published
Apr 18, 2023
Updated
Sep 16, 2024
Vendor
Oracle Corporation
Product
Oracle VM VirtualBox
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 18, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=* <6.1.44
  2. Affected versionversion=* <7.0.8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Oracle Corporation · Oracle VM VirtualBoxversion=* <6.1.44; version=* <7.0.8

Published CVSS scores

3.2Oracle CorporationCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N
6.0Trend Micro Zero Day InitiativeCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

No sourced classifications are available.

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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