CVE-2021-33285

ntfs-3g: Out-of-bounds heap buffer access in ntfs_get_attribute_value() due to incorrect check of bytes_in_use value in MFT records

Published Sep 7, 2021 CVSS 3.1 · 6.7 Medium EPSS < 1% KEV · Not listed
Description
In NTFS-3G versions < 2021.8.22, when a specially crafted NTFS attribute is supplied to the function ntfs_get_attribute_value, a heap buffer overflow can occur allowing for memory disclosure or denial of service. The vulnerability is caused by an out-of-bound buffer access which can be triggered by mounting a crafted ntfs partition. The root cause is a missing consistency check after reading an MFT record : the "bytes_in_use" field should be less than the "bytes_allocated" field. When it is not, the parsing of the records proceeds into the wild.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-2819-1 ntfs-3g security update
Debian DSA Debian DSA DSA-4971-1 ntfs-3g security update
EUVD EUVD EUVD-2021-19996 In NTFS-3G versions < 2021.8.22, when a specially crafted NTFS attribute is supplied to the function ntfs_get_attribute_value, a heap buffer overflow can occur allowing for memory disclosure or denial of service. The vulnerability is caused by an out-of-bound buffer access which can be triggered by mounting a crafted ntfs partition. The root cause is a missing consistency check after reading an MFT record : the "bytes_in_use" field should be less than the "bytes_allocated" field. When it is not, the parsing of the records proceeds into the wild.
History
Type Values Removed Values Added
Weaknesses CWE-20
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

cvssV3_1

{'score': 6.7, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Dec 3, 2025, 2:52 PM
Reserved
May 20, 2021, 12:00 AM
Status
Modified
Published
Sep 7, 2021, 2:15 PM
Modified
Jun 17, 2026, 3:54 AM
Severity
Moderate
Public date
Aug 30, 2021, 12:00 AM