LiveActive security incident?Get immediate response
CVE Record

CVE-2019-19815: In the Linux kernel 5.0.21, mounting a crafted f2fs filesystem image can cause a NULL pointer dereference i...

In the Linux kernel 5.0.21, mounting a crafted f2fs filesystem image can cause a NULL pointer dereference in f2fs_recover_fsync_data in fs/f2fs/recovery.c. This is related to F2FS_P_SB in fs/f2fs/f2fs.h.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2019-19815 is a Linux kernel flaw where mounting a crafted F2FS filesystem image can trigger a NULL pointer dereference. In business terms, this is mainly an availability risk: a vulnerable system could fault or crash when it handles a malicious filesystem image.

Executive priority

Treat this as a targeted availability issue, not a confirmed internet-scale emergency. Prioritize patching where Linux systems handle untrusted storage images or removable media, and rely on vendor advisories for exact exposure.

Technical view

The reported bug affects Linux kernel 5.0.21 in F2FS recovery logic, specifically f2fs_recover_fsync_data in fs/f2fs/recovery.c, related to F2FS_P_SB in fs/f2fs/f2fs.h. The public references include a reproducer repository and an upstream Linux commit, but the CVE record does not provide CVSS, CWE, or complete affected-product metadata.

Likely exposure

Exposure is most plausible on Linux systems that support F2FS and mount untrusted or attacker-supplied filesystem images, including removable media or test images. The bundle only names Linux kernel 5.0.21 and does not define a full affected version range.

Exploitation context

The source bundle does not show CISA KEV listing or confirmed active exploitation. Public material includes a fuzzer proof-of-concept reference, so defenders should assume technical details are available, but not infer widespread real-world exploitation from this bundle alone.

Researcher notes

Evidence is incomplete: the bundle lacks CVSS, CWE, and a full affected-version range. The key technical clue is the F2FS recovery NULL pointer dereference during mount of a crafted image. Avoid overstating impact beyond kernel fault or denial-of-service risk without vendor-specific confirmation.

Mitigation direction

  • Apply vendor kernel updates that include the referenced upstream Linux fix.
  • Check distribution and appliance advisories for exact affected kernel builds.
  • Avoid mounting untrusted F2FS filesystem images on vulnerable systems.
  • Restrict removable-media and image-mount workflows until systems are patched.
  • Review the NetApp advisory if operating NetApp products.

Validation and detection

  • Inventory Linux systems running kernel 5.0.21 or nearby vendor builds.
  • Confirm whether F2FS support is enabled or available on those systems.
  • Identify workflows that mount user-supplied, removable, or test filesystem images.
  • Compare installed kernel packages with vendor advisories and the upstream fix reference.
  • Prioritize systems where filesystem mounting is automated or exposed to lower-trust users.
Prepared
Confidence
medium
Sources
5

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2019-19815 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
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
4Source 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.