Debian LinuxOperating system · Debian
CVE-2021-39259
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 · uneditedA crafted NTFS image can trigger an out-of-bounds access, caused by an unsanitized attribute length in ntfs_inode_lookup_by_name, in NTFS-3G < 2021.8.22.
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 confidenceNTFS-3G versions prior to 2021.8.22 contain an out-of-bounds access vulnerability in ntfs_inode_lookup_by_name when processing NTFS filesystem images. The function fails to properly sanitize attribute length values from crafted images, allowing memory corruption during filesystem metadata parsing.
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
= 9.0= 10.0= 11.0< 2021.8.22CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify installed NTFS-3G package versionRun `dpkg -l ntfs-3g` on Debian/Ubuntu, or `rpm -q ntfs-3g` on RHEL-based systems, or check `ntfs-3g --version` outputAffected if The version displayed is earlier than 2021.8.22 (such as 1:1.1 or 1:1.2 series)
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Confirm Debian Linux version in useRun `cat /etc/debian_version` to identify the Debian releaseAffected if The system runs Debian 9 (stretch), 10 (buster), or 11 (bullseye) and has NTFS-3G installed
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Verify ntfs-3g binary is presentRun `which ntfs-3g` or check for ntfs-3g processes with `ps aux | grep ntfs-3g`Affected if The ntfs-3g binary exists on the system, meaning the vulnerable component is available for use
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Check ntfs-3g library versionRun `ldd $(which ntfs-3g) 2>/dev/null | grep ntfs` or examine the library file directly via `dpkg -L ntfs-3g | grep libntfs`Affected if The linked libntfs library version is prior to 2021.8.22
A system is affected if NTFS-3G version 2021.8.22 or later is NOT installed, and the ntfs-3g tool or library is present for mounting NTFS images.
Generated from the published advisory. Verify against your own configuration.
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 · scoped2021.8.22
Upgrade NTFS-3G to version 2021.8.22 or later. Avoid mounting untrusted or unfamiliar NTFS images until the update is applied.
NTFS-3G >= 2021.8.22
- Update the package repository index: `apt update`
- Upgrade NTFS-3G to the fixed version: `apt upgrade ntfs-3g` or `apt-get install ntfs-3g`
- Verify the installed version is 2021.8.22 or later: `ntfs-3g --version`
- If the package repository does not have the fixed version, download NTFS-3G 2021.8.22 or later from the official source and compile/install manually
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
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-39259 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-39259 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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