Linux KernelOperating system · Linux
CVE-2018-12928
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 · uneditedIn the Linux kernel 4.15.0, a NULL pointer dereference was discovered in hfs_ext_read_extent in hfs.ko. This can occur during a mount of a crafted hfs 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 · high confidenceA NULL pointer dereference vulnerability exists in the HFS filesystem driver (hfs.ko) in Linux kernel 4.15.0. When mounting a specially crafted HFS filesystem, the hfs_ext_read_extent function attempts to dereference a NULL pointer, leading to a kernel panic or potential denial of service.
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
Linux KernelOperating system
= 4.15
Ubuntu LinuxOperating system
= 16.04.4CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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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Check the running kernel versionRun `uname -r` or `cat /proc/version` to see the exact kernel versionAffected if The kernel version is 4.15.x (any minor release)
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Verify if HFS filesystem support is enabledCheck kernel configuration with `zcat /proc/config.gz 2>/dev/null | grep CONFIG_HFS` or check for loaded module with `lsmod | grep hfs`Affected if CONFIG_HFS is set to 'y' (built-in) or 'm' (module) and the hfs.ko module exists or is loaded
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Identify if HFS filesystems are being mountedReview system mount points with `mount | grep hfs` and check any automated mount configurations in /etc/fstab, /etc/auto.master, or container mountsAffected if Any HFS filesystem mounts exist or are configured on the system
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Check for presence of untrusted HFS mediaInspect /media, /mnt, and removable media paths for HFS-formatted volumes using `blkid` or `file -s /dev/sd*`Affected if HFS-formatted media from untrusted sources is connected or could be auto-mounted
The system is affected if it runs kernel 4.15.x AND has HFS filesystem support enabled (built-in or as module) AND could potentially mount a crafted HFS filesystem.
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.
From vendor dataAvoid mounting untrusted or crafted HFS filesystems until the kernel is patched. Apply the upstream kernel fix which adds proper NULL pointer validation in the hfs_ext_read_extent function.
Fix this in Linux Kernel
Scoped from the published advisory
- Consultation4.0 h
- Implementation6.0 h
- Testing12.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,616.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-12928 — 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-2018-12928 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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