Skip to content
Fencer Vulns
medium 6.7

CVE-2021-31916 json

An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux…

published 2021-05-06 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18791

cvss
6.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
0
none known

Summary

An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel before 5.12. A bound check failure allows an attacker with special user (CAP_SYS_ADMIN) privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability.

Patch / fix

  • linux linux_kernel 5.12
  • linux Debian 14, Debian 13, Debian 12 5.10.28-1

debian advisories DEBIAN-CVE-2021-31916

  • linux Ubuntu 18.04 LTS 4.15.0-144.148
  • linux Ubuntu 20.04 LTS 5.4.0-74.83
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1103.110
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1049.51
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1044.47
  • linux-gke Ubuntu 20.04 LTS 5.4.0-1044.46
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1092.94
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1040.41

ubuntu advisories UBUNTU-CVE-2021-31916

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 RHEL 8 4.18.0-348.el8
  • perf RHEL 8 4.18.0-348.el8
  • bpftool RHEL 8 4.18.0-348.el8
  • kernel-core RHEL 8 4.18.0-348.el8
  • kernel-tools RHEL 8 4.18.0-348.el8
  • python3-perf RHEL 8 4.18.0-348.el8
  • kernel-modules RHEL 8 4.18.0-348.el8
  • kernel-zfcpdump RHEL 8 4.18.0-348.el8

red hat advisories RHSA-2021:4356RHSA-2021:4140

  • kernel-rt SLE Real Time 12 SP5 4.12.14-10.70.2
  • kernel-syms-rt SLE Real Time 12 SP5 4.12.14-10.70.2
  • kernel-rt_debug SLE Real Time 12 SP5 4.12.14-10.70.2
  • kernel-source-rt SLE Real Time 12 SP5 4.12.14-10.70.2
  • kernel-rt SLE Micro 5.1, Real Time Module 15 SP3 5.3.18-65.2
  • kernel-syms-rt Real Time Module 15 SP3 5.3.18-65.1
  • kernel-rt_debug Real Time Module 15 SP3 5.3.18-65.2
  • kernel-source-rt Real Time Module 15 SP3 5.3.18-65.2

suse advisories SUSE-SU-2021:3992-1SUSE-SU-2021:3979-1SUSE-SU-2021:3978-1SUSE-SU-2021:3972-1SUSE-SU-2021:3969-1SUSE-SU-2021:3941-1

  • dtb-aarch64 openSUSE Leap 15.3 5.3.18-59.37.1
  • kernel-64kb openSUSE Leap 15.3 5.3.18-59.37.2
  • kernel-syms openSUSE Leap 15.3 5.3.18-59.37.1
  • kernel-obs-qa openSUSE Leap 15.3 5.3.18-59.37.1
  • kernel-source openSUSE Leap 15.3 5.3.18-59.37.2
  • kernel-default openSUSE Leap 15.3 5.3.18-59.37.2
  • kernel-preempt openSUSE Leap 15.3 5.3.18-59.37.2
  • kernel-kvmsmall openSUSE Leap 15.3 5.3.18-59.37.2

opensuse advisories openSUSE-SU-2021:3941-1openSUSE-SU-2021:3876-1openSUSE-SU-2021:3806-1openSUSE-SU-2021:1501-1

  • kernel CBL-Mariner 2.0 5.10.78.1-1

azure linux advisories AZL-6558

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2021-31916 updated cvss 6.7

kernel: out of bounds array access in drivers/md/dm-ioctl.c

  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, kernel-alt, python-perf, +9 more
    affected: workaround, no fix available, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-348.el8, kernel-debuginfo-common-aarch64 4.18.0-348.el8, kernel-debuginfo-common-ppc64le 4.18.0-348.el8 Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-348.el8, kernel 4.18.0-348.el8, bpftool 4.18.0-348.el8, kernel-core 4.18.0-348.el8, kernel-tools 4.18.0-348.el8, python3-perf 4.18.0-348.el8, +15 more
    fixed: vendor fix RHSA-2021:4356
  • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt 4.18.0-348.rt7.130.el8, kernel-rt-core 4.18.0-348.rt7.130.el8, kernel-rt-modules 4.18.0-348.rt7.130.el8, kernel-rt-debug-core 4.18.0-348.rt7.130.el8, kernel-rt-debug-modules 4.18.0-348.rt7.130.el8, kernel-rt-modules-extra 4.18.0-348.rt7.130.el8, +2 more Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt 4.18.0-348.rt7.130.el8, kernel-rt-kvm 4.18.0-348.rt7.130.el8, kernel-rt-core 4.18.0-348.rt7.130.el8, kernel-rt-modules 4.18.0-348.rt7.130.el8, kernel-rt-debug-kvm 4.18.0-348.rt7.130.el8, kernel-rt-debug-core 4.18.0-348.rt7.130.el8, +4 more
    fixed: vendor fix RHSA-2021:4140
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    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

0.70% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.7 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.1 AV:L/AC:L/Au:N/C:P/I:P/A:C

Affected products

  • n/a kernel

Classification

Weakness
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.