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Fencer Vulns
medium 5.5

CVE-2021-29650 json

An issue was discovered in the Linux kernel before 5.11.11.

published 2021-03-30 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-16126

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits
0
none known

Summary

An issue was discovered in the Linux kernel before 5.11.11. The netfilter subsystem allows attackers to cause a denial of service (panic) because net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h lack a full memory barrier upon the assignment of a new table value, aka CID-175e476b8cdf.

Patch / fix

  • linux linux_kernel 5.11.11
  • linux Debian 14, Debian 13, Debian 12 5.10.28-1

debian advisories DEBIAN-CVE-2021-29650

  • linux Ubuntu 18.04 LTS 4.15.0-143.147
  • linux Ubuntu 20.04 LTS 5.4.0-73.82
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1102.109
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1048.50
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1043.46
  • linux-gke Ubuntu 20.04 LTS 5.4.0-1043.45
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1091.93
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1039.40

ubuntu advisories UBUNTU-CVE-2021-29650

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-2021:3327RHSA-2021:4140RHSA-2021:3328

  • kernel-syms SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLE High Performance Computing 15 SP2-LTSS +1 more 5.3.18-150200.24.154.1
  • kernel-source SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLE High Performance Computing 15 SP2-LTSS +1 more 5.3.18-150200.24.154.1
  • kernel-default SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLE Live Patching 15 SP2 +3 more 5.3.18-150200.24.154.1
  • kernel-preempt SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLE High Performance Computing 15 SP2-LTSS +1 more 5.3.18-150200.24.154.1
  • kernel-obs-build SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLE High Performance Computing 15 SP2-LTSS +1 more 5.3.18-150200.24.154.1
  • kernel-default-base SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLE High Performance Computing 15 SP2-LTSS +1 more 5.3.18-150200.24.154.1.150200.9.75.1
  • dtb-aarch64 openSUSE Leap 15.4 5.3.18-150300.59.124.1
  • kernel-64kb SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS, SLE High Performance Computing 15 SP3-ESPOS +1 more 5.3.18-150300.59.124.1

suse advisories SUSE-SU-2023:2651-1SUSE-SU-2023:2611-1SUSE-SU-2021:1977-1SUSE-SU-2021:1975-1SUSE-SU-2021:1915-1SUSE-SU-2021:1624-1

  • kernel-64kb openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-syms openSUSE Leap 15.3 5.3.18-59.5.1
  • kernel-obs-qa openSUSE Leap 15.3 5.3.18-59.5.1
  • kernel-source openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-default openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-preempt openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-kvmsmall openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-zfcpdump openSUSE Leap 15.3 5.3.18-59.5.2

opensuse advisories openSUSE-SU-2021:1977-1openSUSE-SU-2021:1975-1openSUSE-SU-2021:0873-1openSUSE-SU-2021:0716-1

  • kernel CBL-Mariner 2.0 5.10.78.1-1

azure linux advisories AZL-6553

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

  • linux Arch Linux 5.11.11.arch1-1
  • linux-hardened Arch Linux 5.11.11.hardened1-1
  • linux-zen Arch Linux 5.11.11.zen1-1
  • linux-lts Arch Linux 5.10.27-1

arch linux advisories AVG-1747AVG-1748AVG-1749AVG-1750

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-2021-29650 updated cvss 5.5

kernel: lack a full memory barrier upon the assignment of a new table value in net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h may lead to DoS

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, kernel-alt, python-perf, kernel-kdump, kernel-tools, +3 more
    affected: workaround, 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 Client (v. 7) perf 3.10.0-1160.41.1.el7, kernel 3.10.0-1160.41.1.el7, bpftool 3.10.0-1160.41.1.el7, python-perf 3.10.0-1160.41.1.el7, kernel-tools 3.10.0-1160.41.1.el7, kernel-tools-libs 3.10.0-1160.41.1.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.41.1.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.41.1.el7
    fixed: vendor fix RHSA-2021:3327
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1160.41.1.rt56.1181.el7, kernel-rt-trace 3.10.0-1160.41.1.rt56.1181.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.41.1.rt56.1181.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1160.41.1.rt56.1181.el7, kernel-rt-kvm 3.10.0-1160.41.1.rt56.1181.el7, kernel-rt-trace 3.10.0-1160.41.1.rt56.1181.el7, kernel-rt-debug-kvm 3.10.0-1160.41.1.rt56.1181.el7, kernel-rt-trace-kvm 3.10.0-1160.41.1.rt56.1181.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.41.1.rt56.1181.el7
    fixed: vendor fix RHSA-2021:3328
  • 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 Server (v. 7) perf 3.10.0-1160.41.1.el7, kernel 3.10.0-1160.41.1.el7, bpftool 3.10.0-1160.41.1.el7, python-perf 3.10.0-1160.41.1.el7, kernel-kdump 3.10.0-1160.41.1.el7, kernel-tools 3.10.0-1160.41.1.el7, +7 more Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.41.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.41.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.41.1.el7 Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1160.41.1.el7, kernel 3.10.0-1160.41.1.el7, bpftool 3.10.0-1160.41.1.el7, python-perf 3.10.0-1160.41.1.el7, kernel-tools 3.10.0-1160.41.1.el7, kernel-tools-libs 3.10.0-1160.41.1.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.41.1.el7
    fixed: vendor fix RHSA-2021:3327
  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +81 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

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.9 AV:L/AC:L/Au:N/C:N/I:N/A:C

Classification

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.