CVE-2021-23169Network attack vector

Code execution via miscomputed subsampled channel offsets

Published Jun 8, 2021 · Updated Aug 3, 2024

Heap-buffer overflow in exrcheck before OpenEXR 3.0.1 allows context-dependent attackers to execute code via a crafted EXR file. The readScanline and readTile paths derive slice bases from negative data-window offsets without first scaling them by channel xSampling, letting copyIntoFrameBuffer write outside allocated channel vectors. Processing the file is required; Canonical reports that the cited patch affects exrcheck rather than the public library, so library-wide exposure is disputed.

CVSS severity8.8
High
EPSS probability2.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-buffer overflow in exrcheck before OpenEXR 3.0.1 allows context-dependent attackers to execute code via a crafted EXR file. The readScanline and readTile paths derive slice bases from negative data-window offsets without first scaling them by channel xSampling, letting copyIntoFrameBuffer write outside allocated channel vectors. Processing the file is required; Canonical reports that the cited patch affects exrcheck rather than the public library, so library-wide exposure is disputed.

The record

CVE
CVE-2021-23169
Published
Jun 8, 2021
Updated
Aug 3, 2024
Vendor
Academy Software Foundation
Product
OpenEXR
Classifications
CWE-787, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=OpenEXR 3.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Academy Software Foundation · OpenEXRversion=OpenEXR 3.0.1

Published CVSS scores

8.8National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8National Vulnerability DatabaseAV:N/AC:M/Au:N/C:P/I:P/A:P
5.3SUSECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002User Execution: Malicious File

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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