Out-of-bounds reads via malformed NTFS attributes
Published Sep 7, 2021 · Updated Dec 2, 2025
Out-of-bounds reads in NTFS-3G before 2021.8.22 allow local users to access unintended process memory through a crafted NTFS image. The ntfs_attr_find and ntfs_external_attr_find routines parse malformed filesystem attributes without sufficient bounds validation, causing reads beyond the intended attribute data. Exploitation requires local processing of a crafted image; the vendor does not specify a concrete disclosure or crash outcome for this CVE separately from the broader advisory.
Summary
What happened
Out-of-bounds reads in NTFS-3G before 2021.8.22 allow local users to access unintended process memory through a crafted NTFS image. The ntfs_attr_find and ntfs_external_attr_find routines parse malformed filesystem attributes without sufficient bounds validation, causing reads beyond the intended attribute data. Exploitation requires local processing of a crafted image; the vendor does not specify a concrete disclosure or crash outcome for this CVE separately from the broader advisory.
The record
- CVE
- CVE-2021-39258
- Published
- Sep 7, 2021
- Updated
- Dec 2, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-20
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 7, 2021CVE publishedPublication date reported by the CVE source.
- Dec 2, 2025Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Attacks
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Technologies
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