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CVE Record

CVE-2019-19767: The Linux kernel before 5.4.2 mishandles ext4_expand_extra_isize, as demonstrated by use-after-free errors...

The Linux kernel before 5.4.2 mishandles ext4_expand_extra_isize, as demonstrated by use-after-free errors in __ext4_expand_extra_isize and ext4_xattr_set_entry, related to fs/ext4/inode.c and fs/ext4/super.c, aka CID-4ea99936a163.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2019-19767 is a Linux kernel ext4 filesystem bug fixed before kernel 5.4.2. The public record describes use-after-free errors in ext4 extended attribute handling. Impact details and CVSS are not provided, so urgency depends on whether affected kernels are present in business-critical Linux systems.

Executive priority

Treat this as a kernel maintenance priority, not a confirmed emergency from the supplied evidence. Focus on confirming exposure and closing outdated-kernel gaps, especially on important Linux infrastructure and vendor appliances that may lag behind upstream fixes.

Technical view

The issue is tied to ext4_expand_extra_isize, with use-after-free errors in __ext4_expand_extra_isize and ext4_xattr_set_entry, related to fs/ext4/inode.c and fs/ext4/super.c. The upstream fix is associated with Linux commit 4ea99936a163, and multiple vendors issued kernel security updates.

Likely exposure

Exposure is most likely on Linux systems running kernels before 5.4.2 or vendor kernels missing the backported fix, especially where ext4 filesystems are used. Distribution version strings may not be conclusive because vendors often backport kernel fixes.

Exploitation context

The supplied bundle does not identify active exploitation, and KEV is false. Public details establish a kernel memory-safety flaw, but do not provide a confirmed exploitation path, affected configurations beyond the kernel/ext4 context, or practical exploit status.

Researcher notes

The source bundle lacks CVSS, CWE, and detailed impact statements. Analysis should stay anchored to the upstream commit, kernel 5.4.2 changelog, and vendor advisories. Avoid assuming privilege escalation, denial of service, or remote reachability unless a vendor source confirms it.

Mitigation direction

  • Apply the relevant vendor kernel security update for each Linux distribution.
  • Upgrade kernels to a version containing the upstream 4ea99936a163 fix.
  • Check NetApp, Debian, Ubuntu, and openSUSE guidance where applicable.
  • Prioritize externally managed, multi-user, and business-critical Linux systems.
  • Reboot systems after kernel updates where required by vendor guidance.

Validation and detection

  • Inventory Linux kernel versions across servers, appliances, and images.
  • Identify systems using ext4 filesystems or ext4-capable kernels.
  • Confirm vendor packages include the CVE-2019-19767 fix or backport.
  • Review change records for post-update reboots into the fixed kernel.
  • Track exceptions where vendor guidance is unavailable or unclear.
Prepared
Confidence
medium
Sources
12

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-2019-19767 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
13Source 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.