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Debian LinuxOperating system · Debian

CVE-2021-35268

HIGH · 7.8 CVSS v3.1 Published 2021-09-07
Fix available
A fix is available. Upgrade to 2021.8.22 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In NTFS-3G versions < 2021.8.22, when a specially crafted NTFS inode is loaded in the function ntfs_inode_real_open, a heap buffer overflow can occur allowing for code execution and escalation of privileges.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a heap buffer overflow vulnerability in the NTFS-3G driver where loading a specially crafted NTFS inode via the ntfs_inode_real_open function causes overflow, potentially allowing local attackers to achieve code execution and privilege escalation.

MitigationUpgrade NTFS-3G to version 2021.8.22 or later to patch the heap overflow vulnerability in ntfs_inode_real_open.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Debian LinuxOperating system
Affected:= 9.0= 10.0= 11.0
FedoraOperating system
Affected:= 33= 35
Ntfs 3gApplication
Affected:< 2021.8.22

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if NTFS-3G is installed
    Run 'dpkg -l | grep ntfs-3g' on Debian or 'rpm -qa | grep ntfs-3g' on Fedora to list installed NTFS-3G packages
    Affected if No NTFS-3G package is found, then the system is not vulnerable via this vector
  2. Determine installed NTFS-3G version on Debian
    Run 'dpkg -l ntfs-3g' and note the version number displayed (e.g., 1:2017.3.23AR.3-13)
    Affected if The version is earlier than 2021.8.22 (for Tuxera builds) or matches Debian versions 9.0, 10.0, or 11.0 package versions which predate the fix
  3. Determine installed NTFS-3G version on Fedora
    Run 'rpm -qi ntfs-3g' and note the Version and Release fields
    Affected if The version is 2021.8.22 or earlier, matching Fedora 33 or 35 packages
  4. Check NTFS-3G binary version directly
    Run 'ntfs-3g --version' to display the exact version string of the ntfs-3g binary
    Affected if The version output shows a number lower than 2021.8.22
  5. Verify if NTFS volumes have been mounted
    Run 'mount | grep -i ntfs' to list any currently mounted NTFS partitions, or check /etc/fstab for NTFS entries
    Affected if NTFS partitions are mounted using NTFS-3G - the vulnerable code path (ntfs_inode_real_open) is invoked when accessing NTFS filesystems

A system is affected if NTFS-3G is installed with a version earlier than 2021.8.22 AND NTFS volumes are or can be mounted using this driver, as the heap overflow triggers when opening specially crafted NTFS inodes.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2021.8.22 or later
Fixed in 2021.8.22
Interim mitigation

Upgrade NTFS-3G to version 2021.8.22 or later to patch the heap overflow vulnerability in ntfs_inode_real_open.

Recommended fix High confidence

NTFS-3G version 2021.8.22 or later

  1. 1. Check current NTFS-3G version: dpkg -l | grep ntfs-3g (Debian) or rpm -q ntfs-3g (Fedora)
  2. 2. Update package repository metadata: apt update (Debian) or dnf check-update (Fedora)
  3. 3. Upgrade NTFS-3G package: apt install ntfs-3g (Debian) or dnf update ntfs-3g (Fedora)
  4. 4. Verify installed version is 2021.8.22 or later: ntfs-3g --version
  5. 5. If applicable, reboot system or remount any NTFS filesystems to ensure the updated library is loaded

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Debian Linux Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-35268 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data