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Fencer Vulns
high 7.1

CVE-2018-18021 json

arch/arm64/kvm/guest.c in KVM in the Linux kernel before 4.18.12 on the arm64 platform mishandles the KVM_SET_ON_REG ioctl.

published 2018-10-07 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-9760

cvss
7.1
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 48%
public exploits
0
none known

Summary

arch/arm64/kvm/guest.c in KVM in the Linux kernel before 4.18.12 on the arm64 platform mishandles the KVM_SET_ON_REG ioctl. This is exploitable by attackers who can create virtual machines. An attacker can arbitrarily redirect the hypervisor flow of control (with full register control). An attacker can also cause a denial of service (hypervisor panic) via an illegal exception return. This occurs because of insufficient restrictions on userspace access to the core register file, and because PSTATE.M validation does not prevent unintended execution modes.

Patch / fix

  • linux linux_kernel 4.18.12
  • linux Debian 14, Debian 13, Debian 12 4.18.10-2

debian advisories DEBIAN-CVE-2018-18021

  • linux Ubuntu 16.04 LTS 4.4.0-139.165
  • linux Ubuntu 18.04 LTS 4.15.0-47.50
  • linux-hwe Ubuntu 16.04 LTS 4.15.0-47.50~16.04.1
  • linux-oracle Ubuntu 16.04 LTS 4.15.0-1010.12~16.04.1
  • linux-oracle Ubuntu 18.04 LTS 4.15.0-1010.12
  • linux-raspi2 Ubuntu 16.04 LTS 4.4.0-1100.108
  • linux-raspi2 Ubuntu 18.04 LTS 4.15.0-1033.35
  • linux-aws-hwe Ubuntu 16.04 LTS 4.15.0-1035.37~16.04.1

ubuntu advisories UBUNTU-CVE-2018-18021

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-alt RHEL 7 4.14.0-115.2.2.el7a
  • perf RHEL 7 4.14.0-115.2.2.el7a
  • kernel RHEL 7 4.14.0-115.2.2.el7a
  • python-perf RHEL 7 4.14.0-115.2.2.el7a
  • kernel-tools RHEL 7 4.14.0-115.2.2.el7a
  • kernel-tools-libs RHEL 7 4.14.0-115.2.2.el7a
  • kernel-bootwrapper RHEL 7 4.14.0-115.2.2.el7a
  • kernel-abi-whitelists RHEL 7 4.14.0-115.2.2.el7a

red hat advisories RHSA-2018:3656

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-2018-18021 updated cvss 6.7

kernel: Privilege escalation on arm64 via KVM hypervisor

  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) perf 4.14.0-115.2.2.el7a, kernel 4.14.0-115.2.2.el7a, kernel-alt 4.14.0-115.2.2.el7a, python-perf 4.14.0-115.2.2.el7a, kernel-tools 4.14.0-115.2.2.el7a, kernel-tools-libs 4.14.0-115.2.2.el7a, +3 more Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) kernel-debuginfo-common-ppc64le 4.14.0-115.2.2.el7a
    fixed: vendor fix RHSA-2018:3656
  • 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, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 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

0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 7.1 CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
NVD 2.0 3.6 AV:L/AC:L/Au:N/C:N/I:P/A:P

Classification

Weakness
  • CWE-20 Improper Input Validation
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.