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Ubuntu LinuxOperating system · Canonical

CVE-2018-12931

HIGH · 7.8 CVSS v3.0 Published 2018-06-28
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
ntfs_attr_find in the ntfs.ko filesystem driver in the Linux kernel 4.15.0 allows attackers to trigger a stack-based out-of-bounds write and cause a denial of service (kernel oops or panic) or possibly have unspecified other impact via a crafted ntfs filesystem.

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 · moderate confidence

A stack-based out-of-bounds write vulnerability exists in ntfs_attr_find within the NTFS filesystem driver (ntfs.ko) in Linux kernel 4.15.0. Attackers can trigger this by mounting a specially crafted NTFS filesystem, leading to kernel oops or panic, with potential for unspecified additional impact.

MitigationUpgrade Linux kernel to a version that includes the security fix for this vulnerability. If NTFS filesystem support is not required in the environment, consider disabling or blacklisting the ntfs.ko module as a defensive measure.

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
Ubuntu LinuxOperating system
Affected:= 16.04.4
Linux KernelOperating system
Affected:= 4.15

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:3.0/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 installed kernel version
    Run 'uname -r' or 'cat /proc/version' to get the running kernel version. Compare it against the 4.15.x release line.
    Affected if The kernel version is 4.15.0 through 4.15.x (any 4.15 release)
  2. Verify NTFS kernel module availability
    Check if ntfs.ko exists using 'find /lib/modules -name ntfs.ko 2>/dev/null' or check if it is currently loaded with 'lsmod | grep ntfs'.
    Affected if The ntfs.ko module exists in the kernel modules directory for the running kernel
  3. Confirm NTFS support is enabled
    Check kernel configuration for NTFS support: 'cat /boot/config-$(uname -r) | grep -i ntfs' or check if NTFS is usable with 'modprobe ntfs 2>&1' and verify success.
    Affected if NTFS support is compiled as a module (CONFIG_NTFS_FS=m) or built-in (CONFIG_NTFS_FS=y) in the kernel configuration
  4. Check for NTFS mounting capability
    Verify the system can mount NTFS filesystems. Run 'mount -t ntfs -o ro /dev/sdX /mnt 2>&1' (use a test device) or check for ntfs-3g with 'which ntfs-3g'.
    Affected if NTFS filesystem mounting is possible through either the kernel ntfs.ko driver or ntfs-3g userspace tool

A user is affected if they are running a Linux kernel in the 4.15.x line and have NTFS filesystem support enabled (either as ntfs.ko module or built-in), allowing mounting of potentially malicious NTFS images.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Linux kernel to a version that includes the security fix for this vulnerability. If NTFS filesystem support is not required in the environment, consider disabling or blacklisting the ntfs.ko module as a defensive measure.

Fix this in Ubuntu Linux Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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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-2018-12931 in production — separate from our analysis above.

No notes yet

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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
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