CVE-2021-46790Public exploit

Heap corruption via unchecked update-sequence writes

Published May 2, 2022 · Updated Aug 4, 2024

Heap-based buffer overflow in ntfsck in NTFS-3G 2021.8.22 and earlier allows local users to corrupt heap memory via crafted NTFS metadata. The check_file_record function trusts usa_count after merely reporting a length mismatch, then copies update-sequence values beyond the record buffer. Reachability requires ntfsck to process a malicious NTFS file record; the out-of-bounds writes corrupt adjacent heap data under the utility's privileges.

CVSS severity7.8
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in ntfsck in NTFS-3G 2021.8.22 and earlier allows local users to corrupt heap memory via crafted NTFS metadata. The check_file_record function trusts usa_count after merely reporting a length mismatch, then copies update-sequence values beyond the record buffer. Reachability requires ntfsck to process a malicious NTFS file record; the out-of-bounds writes corrupt adjacent heap data under the utility's privileges.

The record

CVE
CVE-2021-46790
Published
May 2, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. May 2, 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 privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P

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
PrivilegesUnavailable
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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