CVE-2021-34141Network attack vector

Spurious warning via prefix-only typecode comparison

Published Dec 17, 2021 · Updated Aug 4, 2024

Incorrect comparison in NumPy before 1.22.0 allows attackers to trigger a spurious deprecation-warning path with crafted type strings. The _convert_from_str function in descriptor.c compares only the known typecode length, so a longer string sharing a deprecated typecode prefix compares equal. The input must reach dtype-string conversion; upstream states that the behavior only controls whether a deprecation warning is emitted and is completely harmless.

CVSS severity5.3
Medium
EPSS probability1.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect comparison in NumPy before 1.22.0 allows attackers to trigger a spurious deprecation-warning path with crafted type strings. The _convert_from_str function in descriptor.c compares only the known typecode length, so a longer string sharing a deprecated typecode prefix compares equal. The input must reach dtype-string conversion; upstream states that the behavior only controls whether a deprecation warning is emitted and is completely harmless.

The record

CVE
CVE-2021-34141
Published
Dec 17, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-697
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 17, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3GitHub Advisory DatabaseCVSS: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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-697Incorrect Comparison

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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