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CVE Record

CVE-2017-18344: The timer_create syscall implementation in kernel/time/posix-timers.c in the Linux kernel before 4.14.8 doe...

The timer_create syscall implementation in kernel/time/posix-timers.c in the Linux kernel before 4.14.8 doesn't properly validate the sigevent->sigev_notify field, which leads to out-of-bounds access in the show_timer function (called when /proc/$PID/timers is read). This allows userspace applications to read arbitrary kernel memory (on a kernel built with CONFIG_POSIX_TIMERS and CONFIG_CHECKPOINT_RESTORE).

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2017-18344 is a Linux kernel information disclosure flaw. A local userspace application could cause reads from kernel memory through /proc/$PID/timers on vulnerable kernels. The issue matters because kernel memory can contain sensitive data and may help other attacks, but the sources do not show active exploitation.

Executive priority

Treat this as a timely kernel maintenance issue, not an emergency based on supplied evidence. Prioritize shared Linux systems and environments running untrusted code because the flaw can expose kernel memory and may aid broader compromise.

Technical view

The timer_create syscall in kernel/time/posix-timers.c before Linux 4.14.8 did not properly validate sigevent->sigev_notify. With CONFIG_POSIX_TIMERS and CONFIG_CHECKPOINT_RESTORE enabled, show_timer could perform out-of-bounds access when /proc/$PID/timers is read, allowing arbitrary kernel memory disclosure from userspace.

Likely exposure

Exposure is limited to Linux kernels before 4.14.8 with the named kernel configuration options enabled. Red Hat and Ubuntu advisories indicate downstream distribution impact, but the bundle does not provide complete affected product or version coverage.

Exploitation context

The bundle includes a public exploit reference, but CISA KEV is false and no supplied source states active exploitation. This appears to require local userspace access, so risk is highest on shared systems, container hosts, and servers where untrusted code can run.

Researcher notes

The core bug is insufficient validation of sigev_notify in timer_create, fixed upstream before 4.14.8. The NVD-style bundle lacks CVSS, CWE, and precise affected CPEs, so validation should rely on kernel version, configuration, and vendor advisory mapping.

Mitigation direction

  • Update to Linux kernel 4.14.8 or a vendor-fixed kernel release.
  • Review Red Hat and Ubuntu advisories for distribution-specific fixed packages.
  • Prioritize systems where untrusted local users or workloads can execute code.
  • Check vendor guidance if running other distributions or custom kernels.
  • Reduce unnecessary local shell or workload access on affected systems.

Validation and detection

  • Inventory kernel versions and identify hosts running releases before 4.14.8.
  • Confirm whether CONFIG_POSIX_TIMERS and CONFIG_CHECKPOINT_RESTORE are enabled.
  • Check package status against applicable Red Hat or Ubuntu advisories.
  • Validate that fixed kernels are installed and booted, not only downloaded.
  • Review shared or multi-tenant Linux systems first.
Prepared
Confidence
high
Sources
9

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.

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CVE-2017-18344 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
14Source 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.