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Fencer Vulns
medium 5.5

CVE-2018-12896 json

An issue was discovered in the Linux kernel through 4.17.3.

published 2018-07-02 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-4849

cvss
5.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

An issue was discovered in the Linux kernel through 4.17.3. An Integer Overflow in kernel/time/posix-timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically makes the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. For example, a local user can cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 4.18.20-1

debian advisories DEBIAN-CVE-2018-12896

  • linux Ubuntu 14.04 LTS 3.13.0-164.214
  • linux Ubuntu 16.04 LTS 4.4.0-141.167
  • linux Ubuntu 18.04 LTS 4.15.0-43.46
  • linux-aws Ubuntu 14.04 LTS 4.4.0-1037.40
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1074.84
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1031.33
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1026.27~16.04.1
  • linux-gcp Ubuntu 18.04 LTS 4.15.0-1026.27

ubuntu advisories UBUNTU-CVE-2018-12896

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-azure SLE Module for Public Cloud 15 4.12.14-5.16.1
  • kernel-syms-azure SLE Module for Public Cloud 15 4.12.14-5.16.1
  • kernel-source-azure SLE Module for Public Cloud 15 4.12.14-5.16.1
  • kernel-ec2 SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 3.0.101-0.47.106.56.1
  • kernel-pae SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 3.0.101-0.47.106.56.1
  • kernel-xen SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 3.0.101-0.47.106.56.1
  • kernel-syms SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 3.0.101-0.47.106.56.1
  • kernel-trace SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 3.0.101-0.47.106.56.1

suse advisories SUSE-SU-2018:2908-2SUSE-SU-2018:3961-1SUSE-SU-2018:3618-1SUSE-SU-2018:3084-1SUSE-SU-2018:3088-1SUSE-SU-2018:3083-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-12896 updated cvss 3.3

kernel: Integer overflow in kernel/time/posix-timers.c

  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, kernel-alt, python-perf, +9 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-core, kernel-tools, python3-perf, +17 more Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/lcytxw/bug_repro/tree/master/bug_200189 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 5.5 CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.