CVE-2021-45829Public exploit

h5stat crash via uninitialized link-table entries

Published Jan 3, 2022 · Updated Aug 4, 2024

Improper memory initialization in HDF5 1.13.1-1 allows attackers to crash h5stat by processing a crafted HDF5 file. H5G__compact_build_table allocates its H5O_link_t table without zeroing entries, so link cleanup passes an uninitialized pointer to free. Execution requires a user or application to run h5stat on the file, and the resulting segmentation fault terminates that process.

CVSS severity5.5
Medium
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper memory initialization in HDF5 1.13.1-1 allows attackers to crash h5stat by processing a crafted HDF5 file. H5G__compact_build_table allocates its H5O_link_t table without zeroing entries, so link cleanup passes an uninitialized pointer to free. Execution requires a user or application to run h5stat on the file, and the resulting segmentation fault terminates that process.

The record

CVE
CVE-2021-45829
Published
Jan 3, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-404, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 3, 2022CVE 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 vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-404Improper Resource Shutdown or Release
T1499.004Application 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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