CVE-2024-21639Network attack vector

Out-of-sandbox memory read via undersized shared memory

Published Jan 12, 2024 · Updated Aug 1, 2024

Out-of-bounds read in CEF before 121 allows attackers controlling the GPU process to read beyond a shared-memory buffer. CefLayeredWindowUpdaterOSR maps a GPU-supplied region without verifying that its size meets the byte count calculated from the supplied pixel dimensions, and Draw passes that mapping to OnPaint. Exploitation requires OSR to be enabled and prior compromise of the GPU process; the documented consequence is an out-of-sandbox memory read.

CVSS severity9.6
Critical
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in CEF before 121 allows attackers controlling the GPU process to read beyond a shared-memory buffer. CefLayeredWindowUpdaterOSR maps a GPU-supplied region without verifying that its size meets the byte count calculated from the supplied pixel dimensions, and Draw passes that mapping to OnPaint. Exploitation requires OSR to be enabled and prior compromise of the GPU process; the documented consequence is an out-of-sandbox memory read.

The record

CVE
CVE-2024-21639
Published
Jan 12, 2024
Updated
Aug 1, 2024
Vendor
Chromium Embedded Framework
Product
Chromium Embedded Framework (CEF)
Classifications
CWE-125
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 12, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 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=-
  2. Affected versionversion=< commit 1f55d2e

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Chromium Embedded Framework · Chromium Embedded Framework (CEF)version=-; version=< commit 1f55d2e

Published CVSS scores

9.6NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

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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