CVE-2021-37646Public exploit

Local service interruption via oversized string allocation

Published Aug 12, 2021 · Updated Aug 4, 2024

Incorrect numeric conversion in Google TensorFlow StringNGrams before 2.3.4, 2.4.0 through 2.4.2, and 2.5.0 allows local users to interrupt service. StringNGrams accepts negative ngram_widths, computes a negative buffer length, and passes it to the unsigned TF_TString_Reserve size parameter, producing a huge allocation request. Local access capable of invoking the operation with controlled arguments is required, and exploitation interrupts only the hosting process or service through memory exhaustion or allocation failure.

CVSS severity5.5
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect numeric conversion in Google TensorFlow StringNGrams before 2.3.4, 2.4.0 through 2.4.2, and 2.5.0 allows local users to interrupt service. StringNGrams accepts negative ngram_widths, computes a negative buffer length, and passes it to the unsigned TF_TString_Reserve size parameter, producing a huge allocation request. Local access capable of invoking the operation with controlled arguments is required, and exploitation interrupts only the hosting process or service through memory exhaustion or allocation failure.

The record

CVE
CVE-2021-37646
Published
Aug 12, 2021
Updated
Aug 4, 2024
Vendor
Google
Product
TensorFlow
Classifications
CWE-681, T1499.004
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

2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:P
5.5GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-681Incorrect Conversion between Numeric Types
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

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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