CVE-2021-37657

Undefined behavior via empty k tensor

Published Aug 12, 2021 · Updated Aug 4, 2024

CWE-824 in Google TensorFlow versions before 2.3.4, 2.4.3, or 2.5.1 allows local users to trigger undefined behavior in MatrixDiagV* operations. The kernels accept scalar or vector k tensors without checking element count, then dereference the first element of an empty tensor and bind a reference to null. Exploitation requires local ability to invoke the raw operation; the documented consequence is undefined behavior that can affect process integrity or availability.

CVSS severity7.8
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CWE-824 in Google TensorFlow versions before 2.3.4, 2.4.3, or 2.5.1 allows local users to trigger undefined behavior in MatrixDiagV* operations. The kernels accept scalar or vector k tensors without checking element count, then dereference the first element of an empty tensor and bind a reference to null. Exploitation requires local ability to invoke the raw operation; the documented consequence is undefined behavior that can affect process integrity or availability.

The record

CVE
CVE-2021-37657
Published
Aug 12, 2021
Updated
Aug 4, 2024
Vendor
Google
Product
TensorFlow
Classifications
CWE-824
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=< 2.3.4
  2. Affected versionversion=>= 2.4.0, < 2.4.3
  3. Affected versionversion=>= 2.5.0, < 2.5.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google · TensorFlowversion=< 2.3.4; version=>= 2.4.0, < 2.4.3; version=>= 2.5.0, < 2.5.1

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.1GitHubCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-824CWE-824: Access of Uninitialized Pointer

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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