CVE-2021-46243Public exploitNetwork attack vector

Application crash via mismatched enum datatype sizes

Published Jan 21, 2022 · Updated Aug 4, 2024

NULL pointer dereference in HDF5 1.13.1-1 allows context-dependent attackers to crash an application via a crafted HDF5 file. H5O__dtype_decode_helper accepts an enum datatype whose parent size differs, so later enum-value access derives an invalid copy length and dereferences untrusted memory. The file must be opened by an HDF5-using process; the demonstrated outcome is a segmentation-fault crash, with no sourced confidentiality or integrity impact.

CVSS severity6.5
Medium
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in HDF5 1.13.1-1 allows context-dependent attackers to crash an application via a crafted HDF5 file. H5O__dtype_decode_helper accepts an enum datatype whose parent size differs, so later enum-value access derives an invalid copy length and dereferences untrusted memory. The file must be opened by an HDF5-using process; the demonstrated outcome is a segmentation-fault crash, with no sourced confidentiality or integrity impact.

The record

CVE
CVE-2021-46243
Published
Jan 21, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 21, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
4.4SUSECVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/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 exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

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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