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Fencer Vulns
high 7.8

CVE-2021-3347 json

An issue was discovered in the Linux kernel through 5.10.11.

published 2021-01-29 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26678

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 72%
public exploits
0
none known

Summary

An issue was discovered in the Linux kernel through 5.10.11. PI futexes have a kernel stack use-after-free during fault handling, allowing local users to execute code in the kernel, aka CID-34b1a1ce1458.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 5.10.12-1

debian advisories DEBIAN-CVE-2021-3347

  • linux Ubuntu 16.04 LTS 4.4.0-208.240
  • linux Ubuntu 18.04 LTS 4.15.0-141.145
  • linux Ubuntu 20.04 LTS 5.4.0-67.75
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1126.140
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1098.105
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1039.41
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1097.110~16.04.1
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1038.41

ubuntu advisories UBUNTU-CVE-2021-3347

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 4.14.0-115.36.1.el7a
  • perf RHEL 7 4.14.0-115.36.1.el7a
  • kernel RHEL 7 4.14.0-115.36.1.el7a
  • python-perf RHEL 7 4.14.0-115.36.1.el7a
  • kernel-tools RHEL 7 4.14.0-115.36.1.el7a
  • kernel-tools-libs RHEL 7 4.14.0-115.36.1.el7a
  • kernel-bootwrapper RHEL 7 4.14.0-115.36.1.el7a
  • kernel-debuginfo-common-ppc64le RHEL 7 4.14.0-115.36.1.el7a

red hat advisories RHSA-2021:2106RHSA-2021:2099RHSA-2021:1379RHSA-2021:3522RHSA-2021:2314RHSA-2021:2316

  • kgraft-patch-SLE12-SP2_Update_36 SLES for SAP 12 SP2, SLES 12 SP2-LTSS, OpenStack Cloud 7 7-2.2
  • kernel-syms SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +6 more 4.12.14-197.83.1
  • kernel-source SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +6 more 4.12.14-197.83.1
  • kernel-default SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +8 more 4.12.14-197.83.1
  • kernel-zfcpdump SLES 15 SP1-LTSS, Manager Server 4.0 4.12.14-197.83.1
  • kernel-obs-build SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +6 more 4.12.14-197.83.1
  • kernel-syms SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 4.4.180-94.138.1
  • kernel-source SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 4.4.180-94.138.1

suse advisories SUSE-SU-2021:0868-1SUSE-SU-2021:0853-1SUSE-SU-2021:0859-1SUSE-SU-2021:0818-1SUSE-SU-2021:0809-1SUSE-SU-2021:0849-1

  • kernel-syms openSUSE Leap 15.2 5.3.18-lp152.63.1
  • kernel-obs-qa openSUSE Leap 15.2 5.3.18-lp152.63.1
  • kernel-source openSUSE Leap 15.2 5.3.18-lp152.63.1
  • kernel-default openSUSE Leap 15.2 5.3.18-lp152.63.1
  • kernel-preempt openSUSE Leap 15.2 5.3.18-lp152.63.1
  • kernel-kvmsmall openSUSE Leap 15.2 5.3.18-lp152.63.1
  • kernel-obs-build openSUSE Leap 15.2 5.3.18-lp152.63.1
  • kernel-default-base openSUSE Leap 15.2 5.3.18-lp152.63.1.lp152.8.21.1

opensuse advisories openSUSE-SU-2021:0241-1

  • kernel-abi-whitelists AlmaLinux 8 4.18.0-240.22.1.el8_3

almalinux advisories ALSA-2021:1093

  • linux Arch Linux 5.10.12.arch1-1
  • linux-hardened Arch Linux 5.10.12.hardened1-1
  • linux-zen Arch Linux 5.10.12.zen1-1
  • linux-lts Arch Linux 5.4.94-1

arch linux advisories AVG-1506AVG-1507AVG-1508AVG-1509

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-2021-3347 updated cvss 7.0

kernel: Use after free via PI futex state

  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-240.22.1.el8_3, kernel-debuginfo-common-aarch64 4.18.0-240.22.1.el8_3, kernel-debuginfo-common-ppc64le 4.18.0-240.22.1.el8_3
    fixed: vendor fix RHSA-2021:1093
  • Red Hat CodeReady Linux Builder EUS (v. 8.1) kernel-debuginfo-common-x86_64 4.18.0-147.48.1.el8_1, kernel-debuginfo-common-aarch64 4.18.0-147.48.1.el8_1, kernel-debuginfo-common-ppc64le 4.18.0-147.48.1.el8_1
    fixed: vendor fix RHSA-2021:2106
  • Red Hat CodeReady Linux Builder EUS (v. 8.2) kernel-debuginfo-common-x86_64 4.18.0-193.51.1.el8_2, kernel-debuginfo-common-aarch64 4.18.0-193.51.1.el8_2, kernel-debuginfo-common-ppc64le 4.18.0-193.51.1.el8_2
    fixed: vendor fix RHSA-2021:1272
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-240.22.1.el8_3, kernel 4.18.0-240.22.1.el8_3, bpftool 4.18.0-240.22.1.el8_3, kernel-core 4.18.0-240.22.1.el8_3, kernel-tools 4.18.0-240.22.1.el8_3, python3-perf 4.18.0-240.22.1.el8_3, +15 more
    fixed: vendor fix RHSA-2021:1093
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.1) perf 4.18.0-147.48.1.el8_1, kernel 4.18.0-147.48.1.el8_1, bpftool 4.18.0-147.48.1.el8_1, kernel-core 4.18.0-147.48.1.el8_1, kernel-tools 4.18.0-147.48.1.el8_1, python3-perf 4.18.0-147.48.1.el8_1, +23 more
    fixed: vendor fix RHSA-2021:2106
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) perf 4.18.0-193.51.1.el8_2, kernel 4.18.0-193.51.1.el8_2, bpftool 4.18.0-193.51.1.el8_2, kpatch-patch-4_18_0-193 1-13.el8, kernel-core 4.18.0-193.51.1.el8_2, kernel-tools 4.18.0-193.51.1.el8_2, +28 more
    fixed: vendor fix RHSA-2021:1272
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1160.31.1.el7, kernel 3.10.0-1160.31.1.el7, bpftool 3.10.0-1160.31.1.el7, python-perf 3.10.0-1160.31.1.el7, kernel-tools 3.10.0-1160.31.1.el7, kernel-tools-libs 3.10.0-1160.31.1.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.31.1.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.31.1.el7
    fixed: vendor fix RHSA-2021:2314
  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) perf 4.14.0-115.36.1.el7a, kernel 4.14.0-115.36.1.el7a, kernel-alt 4.14.0-115.36.1.el7a, python-perf 4.14.0-115.36.1.el7a, kernel-tools 4.14.0-115.36.1.el7a, kernel-tools-libs 4.14.0-115.36.1.el7a, +2 more Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) kernel-debuginfo-common-ppc64le 4.14.0-115.36.1.el7a
    fixed: vendor fix RHSA-2021:1379
show 28 more
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1160.31.1.rt56.1169.el7, kernel-rt-trace 3.10.0-1160.31.1.rt56.1169.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.31.1.rt56.1169.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1160.31.1.rt56.1169.el7, kernel-rt-kvm 3.10.0-1160.31.1.rt56.1169.el7, kernel-rt-trace 3.10.0-1160.31.1.rt56.1169.el7, kernel-rt-debug-kvm 3.10.0-1160.31.1.rt56.1169.el7, kernel-rt-trace-kvm 3.10.0-1160.31.1.rt56.1169.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.31.1.rt56.1169.el7
    fixed: vendor fix RHSA-2021:2316
  • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-core 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-modules 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-debug-core 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-debug-modules 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-modules-extra 4.18.0-240.22.1.rt7.77.el8_3, +2 more
    fixed: vendor fix RHSA-2021:1081
  • Red Hat Enterprise Linux Real Time EUS (v. 8.2) kernel-rt 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-core 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-modules 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-debug-core 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-debug-modules 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-modules-extra 4.18.0-193.51.1.rt13.101.el8_2, +2 more
    fixed: vendor fix RHSA-2021:1279
  • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-kvm 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-core 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-modules 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-debug-kvm 4.18.0-240.22.1.rt7.77.el8_3, kernel-rt-debug-core 4.18.0-240.22.1.rt7.77.el8_3, +4 more
    fixed: vendor fix RHSA-2021:1081
  • Red Hat Enterprise Linux Real Time for NFV EUS (v. 8.2) kernel-rt 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-kvm 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-core 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-modules 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-debug-kvm 4.18.0-193.51.1.rt13.101.el8_2, kernel-rt-debug-core 4.18.0-193.51.1.rt13.101.el8_2, +4 more
    fixed: vendor fix RHSA-2021:1279
  • Red Hat Enterprise Linux Server (v. 6 ELS) perf 2.6.32-754.41.2.el6, kernel 2.6.32-754.41.2.el6, kernel-kdump 2.6.32-754.41.2.el6, kernel-firmware 2.6.32-754.41.2.el6, kernel-abi-whitelists 2.6.32-754.41.2.el6, kernel-debuginfo-common-i686 2.6.32-754.41.2.el6, +2 more
    fixed: vendor fix RHSA-2021:2735
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1160.31.1.el7, kernel 3.10.0-1160.31.1.el7, bpftool 3.10.0-1160.31.1.el7, kpatch-patch-3_10_0-1160 1-6.el7, python-perf 3.10.0-1160.31.1.el7, kernel-kdump 3.10.0-1160.31.1.el7, +16 more
    fixed: vendor fix RHSA-2021:2314
  • Red Hat Enterprise Linux Server AUS (v. 7.2) perf 3.10.0-327.100.1.el7, kernel 3.10.0-327.100.1.el7, python-perf 3.10.0-327.100.1.el7, kernel-tools 3.10.0-327.100.1.el7, kernel-tools-libs 3.10.0-327.100.1.el7, kernel-abi-whitelists 3.10.0-327.100.1.el7, +1 more
    fixed: vendor fix RHSA-2021:3399
  • Red Hat Enterprise Linux Server AUS (v. 7.3) perf 3.10.0-514.90.2.el7, kernel 3.10.0-514.90.2.el7, python-perf 3.10.0-514.90.2.el7, kernel-tools 3.10.0-514.90.2.el7, kernel-tools-libs 3.10.0-514.90.2.el7, kernel-abi-whitelists 3.10.0-514.90.2.el7, +1 more
    fixed: vendor fix RHSA-2021:2733
  • Red Hat Enterprise Linux Server AUS (v. 7.4) perf 3.10.0-693.90.2.el7, kernel 3.10.0-693.90.2.el7, python-perf 3.10.0-693.90.2.el7, kernel-tools 3.10.0-693.90.2.el7, kernel-tools-libs 3.10.0-693.90.2.el7, kernel-abi-whitelists 3.10.0-693.90.2.el7, +1 more
    fixed: vendor fix RHSA-2021:2732
  • Red Hat Enterprise Linux Server AUS (v. 7.6) perf 3.10.0-957.78.2.el7, kernel 3.10.0-957.78.2.el7, bpftool 3.10.0-957.78.2.el7, python-perf 3.10.0-957.78.2.el7, kernel-tools 3.10.0-957.78.2.el7, kernel-tools-libs 3.10.0-957.78.2.el7, +2 more
    fixed: vendor fix RHSA-2021:2730
  • Red Hat Enterprise Linux Server AUS (v. 7.7) perf 3.10.0-1062.56.1.el7, kernel 3.10.0-1062.56.1.el7, bpftool 3.10.0-1062.56.1.el7, python-perf 3.10.0-1062.56.1.el7, kernel-tools 3.10.0-1062.56.1.el7, kernel-tools-libs 3.10.0-1062.56.1.el7, +2 more
    fixed: vendor fix RHSA-2021:3522
  • Red Hat Enterprise Linux Server E4S (v. 7.4) perf 3.10.0-693.90.2.el7, kernel 3.10.0-693.90.2.el7, python-perf 3.10.0-693.90.2.el7, kernel-tools 3.10.0-693.90.2.el7, kernel-tools-libs 3.10.0-693.90.2.el7, kernel-bootwrapper 3.10.0-693.90.2.el7, +3 more
    fixed: vendor fix RHSA-2021:2732
  • Red Hat Enterprise Linux Server E4S (v. 7.6) perf 3.10.0-957.78.2.el7, kernel 3.10.0-957.78.2.el7, python-perf 3.10.0-957.78.2.el7, kernel-tools 3.10.0-957.78.2.el7, kpatch-patch-3_10_0-957_58_2 1-4.el7, kpatch-patch-3_10_0-957_61_1 1-4.el7, +12 more
    fixed: vendor fix RHSA-2021:2730
  • Red Hat Enterprise Linux Server E4S (v. 7.7) perf 3.10.0-1062.56.1.el7, kernel 3.10.0-1062.56.1.el7, bpftool 3.10.0-1062.56.1.el7, python-perf 3.10.0-1062.56.1.el7, kernel-tools 3.10.0-1062.56.1.el7, kpatch-patch-3_10_0-1062_36_1 1-5.el7, +13 more
    fixed: vendor fix RHSA-2021:3522
  • Red Hat Enterprise Linux Server Optional (v. 6 ELS) python-perf 2.6.32-754.41.2.el6, kernel-debuginfo-common-i686 2.6.32-754.41.2.el6, kernel-debuginfo-common-s390x 2.6.32-754.41.2.el6, kernel-debuginfo-common-x86_64 2.6.32-754.41.2.el6
    fixed: vendor fix RHSA-2021:2735
  • Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.31.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.31.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.31.1.el7
    fixed: vendor fix RHSA-2021:2314
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.2) kernel-debuginfo-common-x86_64 3.10.0-327.100.1.el7
    fixed: vendor fix RHSA-2021:3399
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.3) kernel-debuginfo-common-x86_64 3.10.0-514.90.2.el7
    fixed: vendor fix RHSA-2021:2733
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.4) kernel-debuginfo-common-x86_64 3.10.0-693.90.2.el7
    fixed: vendor fix RHSA-2021:2732
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.6) kernel-debuginfo-common-x86_64 3.10.0-957.78.2.el7
    fixed: vendor fix RHSA-2021:2730
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.7) kernel-debuginfo-common-x86_64 3.10.0-1062.56.1.el7
    fixed: vendor fix RHSA-2021:3522
  • Red Hat Enterprise Linux Server Optional E4S (v. 7.4) kernel-debuginfo-common-x86_64 3.10.0-693.90.2.el7, kernel-debuginfo-common-ppc64le 3.10.0-693.90.2.el7
    fixed: vendor fix RHSA-2021:2732
  • Red Hat Enterprise Linux Server Optional E4S (v. 7.6) kernel-debuginfo-common-x86_64 3.10.0-957.78.2.el7, kernel-debuginfo-common-ppc64le 3.10.0-957.78.2.el7
    fixed: vendor fix RHSA-2021:2730
  • Red Hat Enterprise Linux Server Optional E4S (v. 7.7) kernel-debuginfo-common-x86_64 3.10.0-1062.56.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1062.56.1.el7
    fixed: vendor fix RHSA-2021:3522
  • Red Hat Enterprise Linux Server Optional TUS (v. 7.4) kernel-debuginfo-common-x86_64 3.10.0-693.90.2.el7
    fixed: vendor fix RHSA-2021:2732
  • Red Hat Enterprise Linux Server Optional TUS (v. 7.6) kernel-debuginfo-common-x86_64 3.10.0-957.78.2.el7
    fixed: vendor fix RHSA-2021:2730
  • Red Hat Enterprise Linux Server Optional TUS (v. 7.7) kernel-debuginfo-common-x86_64 3.10.0-1062.56.1.el7
    fixed: vendor fix RHSA-2021:3522

5 more fixed, 2 more not affected in the full advisory

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

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
15 mo ago

Exploit prediction

1.36% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • openwall.com http://www.openwall.com/lists/oss-security/2021/02/01/4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

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.