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CVE Record

CVE-2019-19377: In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image, performing some operations, and unmo...

In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image, performing some operations, and unmounting can lead to a use-after-free in btrfs_queue_work in fs/btrfs/async-thread.c.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2019-19377 is a Linux kernel Btrfs flaw triggered by handling a crafted filesystem image. An attacker would need a path to get that image mounted and processed. Sources do not provide CVSS, active exploitation, or complete affected-version detail, so urgency depends on whether systems allow Btrfs mounting or untrusted disk images.

Executive priority

Treat this as a targeted kernel-hardening issue, not an internet-wide emergency based on current evidence. Prioritize patching systems that handle untrusted images or expose mount workflows, and include remaining systems in normal kernel update cycles.

Technical view

The CVE describes a use-after-free in btrfs_queue_work in fs/btrfs/async-thread.c in Linux kernel 5.0.21. The trigger sequence is mounting a crafted Btrfs filesystem image, performing operations, and unmounting it. Ubuntu, Debian LTS, and NetApp issued advisories or confirmations, but the supplied record lacks CVSS, CWE, and normalized affected CPEs.

Likely exposure

Exposure is most plausible on Linux systems where Btrfs is enabled and users, services, or automation can mount or process untrusted filesystem images. Typical enterprise exposure may be limited by mount privileges, but appliances, build systems, forensic workstations, and virtualization workflows should be checked.

Exploitation context

The supplied sources do not state active exploitation, and this CVE is not marked KEV. Public reference material includes a proof-oriented repository, but the safe takeaway is that exploitation requires crafted filesystem input and mount-related capability, not ordinary remote network access.

Researcher notes

Evidence is incomplete: no CVSS vector, CWE, or normalized affected CPEs are provided. Analysis should center on Btrfs reachability, mount privilege boundaries, kernel package lineage, and whether vendor advisories map to the organization’s deployed kernels.

Mitigation direction

  • Apply vendor kernel updates from Ubuntu, Debian, NetApp, or your Linux distributor.
  • Restrict mounting of untrusted filesystem images to controlled, isolated systems.
  • Disable or limit Btrfs support where it is not operationally required.
  • Review vendor guidance for exact affected kernels and fixed package versions.

Validation and detection

  • Inventory Linux systems with Btrfs enabled or Btrfs modules available.
  • Identify workflows that mount user-supplied, downloaded, or external disk images.
  • Confirm installed kernel packages include relevant vendor security updates.
  • Check appliances against NetApp advisory applicability and remediation status.
Prepared
Confidence
medium
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2019-19377 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
7Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.