CVE-2021-37501Public exploitNetwork attack vector

Process crash via truncated attribute data size

Published Feb 3, 2023 · Updated Mar 26, 2025

Heap buffer overflow in HDF5 h5dump 1.12.0 through 1.13.0 allows attackers to crash the process via a malformed HDF5 file. H5O__attr_decode multiplies an attacker-controlled dataspace dimension by the datatype size, truncates the overflowing result to zero, and later reads attribute data into the undersized heap allocation. Exploitation requires an affected parser path to process the crafted file and is bounded to a process crash in the published assessment.

CVSS severity7.5
High
EPSS probability1.54%
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 HDF5 h5dump 1.12.0 through 1.13.0 allows attackers to crash the process via a malformed HDF5 file. H5O__attr_decode multiplies an attacker-controlled dataspace dimension by the datatype size, truncates the overflowing result to zero, and later reads attribute data into the undersized heap allocation. Exploitation requires an affected parser path to process the crafted file and is bounded to a process crash in the published assessment.

The record

CVE
CVE-2021-37501
Published
Feb 3, 2023
Updated
Mar 26, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 3, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 2025Record 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

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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.

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 exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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