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CVE Record

CVE-2019-19241: In the Linux kernel before 5.4.2, the io_uring feature leads to requests that inadvertently have UID 0 and...

In the Linux kernel before 5.4.2, the io_uring feature leads to requests that inadvertently have UID 0 and full capabilities, aka CID-181e448d8709. This is related to fs/io-wq.c, fs/io_uring.c, and net/socket.c. For example, an attacker can bypass intended restrictions on adding an IPv4 address to the loopback interface. This occurs because IORING_OP_SENDMSG operations, although requested in the context of an unprivileged user, are sometimes performed by a kernel worker thread without considering that context.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This Linux kernel flaw could let actions requested by an unprivileged user run inside a kernel worker with UID 0 and full capabilities. In business terms, affected systems may not enforce expected local privilege boundaries. The source bundle does not provide CVSS scoring or confirm active exploitation.

Executive priority

Prioritize remediation where untrusted users, containers, build jobs, or shared workloads can run local code. This is not remotely exploitable from the supplied evidence, but the impact crosses a core operating-system privilege boundary.

Technical view

Before Linux kernel 5.4.2, io_uring requests, especially IORING_OP_SENDMSG, could be performed by io-wq worker context without preserving the caller's unprivileged credentials. The CVE cites fs/io-wq.c, fs/io_uring.c, and net/socket.c, with upstream fixes referenced by commits 181e448d8709 and d69e07793f89.

Likely exposure

Likely exposure is Linux systems running kernels before 5.4.2 where io_uring is available. Vendor-maintained kernels may have backported fixes, so version strings alone are not enough. Ubuntu and NetApp advisories indicate downstream vendor impact tracking existed.

Exploitation context

The bundle does not include KEV status or any cited confirmation of active exploitation. Public technical discussion and upstream commits exist, so defenders should treat this as a known local privilege boundary issue, not a theoretical parser bug.

Researcher notes

The key behavior is credential confusion between the unprivileged io_uring submitter and the kernel worker executing socket-related work. The cited example is bypassing restrictions on adding an IPv4 address to loopback. Evidence is strong on root-cause direction, but scoring and exploitation prevalence are incomplete.

Mitigation direction

  • Upgrade to a vendor kernel containing the upstream io_uring credential fixes.
  • Check Ubuntu, NetApp, or relevant vendor advisories for backported fixed builds.
  • Prioritize multi-user Linux servers and systems running untrusted local workloads.
  • If patching is delayed, review vendor guidance for temporary exposure reduction.

Validation and detection

  • Inventory Linux kernel versions and vendor package release levels.
  • Confirm whether io_uring support is present on affected hosts.
  • Map systems against vendor advisories, not only upstream version numbers.
  • Verify installed kernels include fixes for commits 181e448d8709 and d69e07793f89.
Prepared
Confidence
medium
Sources
7

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

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CVE-2019-19241 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

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