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Fencer Vulns
medium 6.0

CVE-2020-25211 json

In the Linux kernel through 5.8.7, local attackers able to inject conntrack netlink configuration could overflow a local buffer, causing cr…

published 2020-09-09 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-17901

cvss
6.0
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits
0
none known

Summary

In the Linux kernel through 5.8.7, local attackers able to inject conntrack netlink configuration could overflow a local buffer, causing crashes or triggering use of incorrect protocol numbers in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c, aka CID-1cc5ef91d2ff.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 5.8.14-1

debian advisories DEBIAN-CVE-2020-25211

  • linux Ubuntu 16.04 LTS 4.4.0-197.229
  • linux Ubuntu 18.04 LTS 4.15.0-126.129
  • linux Ubuntu 20.04 LTS 5.4.0-56.62
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1118.132
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1088.93
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1030.31
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1088.101~16.04.1
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1030.32

ubuntu advisories UBUNTU-CVE-2020-25211

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 7 3.10.0-1160.21.1.el7
  • perf RHEL 7 3.10.0-1160.21.1.el7
  • bpftool RHEL 7 3.10.0-1160.21.1.el7
  • python-perf RHEL 7 3.10.0-1160.21.1.el7
  • kernel-kdump RHEL 7 3.10.0-1160.21.1.el7
  • kernel-tools RHEL 7 3.10.0-1160.21.1.el7
  • kernel-tools-libs RHEL 7 3.10.0-1160.21.1.el7
  • kernel-bootwrapper RHEL 7 3.10.0-1160.21.1.el7

red hat advisories RHSA-2021:0763RHSA-2021:0765RHSA-2021:0774RHSA-2021:0856RHSA-2021:0857RHSA-2021:2164

  • 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
  • kernel-default SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +5 more 4.4.180-94.138.1
  • kgraft-patch-SLE12-SP3_Update_37 SLES for SAP 12 SP3, SLES 12 SP3-LTSS, OpenStack Cloud Crowbar 8 +3 more 1-4.3.1
  • kernel-syms SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.66.1
  • kernel-source SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.66.1
  • kernel-default SLES for SAP 15, SLES 15-LTSS, SLE Live Patching 15 +3 more 4.12.14-150.66.1
  • kernel-vanilla SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.66.1

suse advisories SUSE-SU-2021:14630-1SUSE-SU-2021:0452-1SUSE-SU-2021:0438-1SUSE-SU-2021:0437-1SUSE-SU-2021:0434-1SUSE-SU-2021:0427-1

  • 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

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-2020-25211 updated cvss 6.7

kernel: Local buffer overflow in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.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, kernel-alt, python-perf, kernel-kdump, kernel-tools, +3 more
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise MRG 2 kernel
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-240.10.1.el8_3, kernel-debuginfo-common-aarch64 4.18.0-240.10.1.el8_3, kernel-debuginfo-common-ppc64le 4.18.0-240.10.1.el8_3
    fixed: vendor fix RHSA-2021:0003
  • Red Hat CodeReady Linux Builder EUS (v. 8.1) kernel-debuginfo-common-x86_64 4.18.0-147.38.1.el8_1, kernel-debuginfo-common-aarch64 4.18.0-147.38.1.el8_1, kernel-debuginfo-common-ppc64le 4.18.0-147.38.1.el8_1
    fixed: vendor fix RHSA-2021:0184
  • Red Hat CodeReady Linux Builder EUS (v. 8.2) kernel-debuginfo-common-x86_64 4.18.0-193.46.1.el8_2, kernel-debuginfo-common-aarch64 4.18.0-193.46.1.el8_2, kernel-debuginfo-common-ppc64le 4.18.0-193.46.1.el8_2
    fixed: vendor fix RHSA-2021:0765
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-240.10.1.el8_3, kernel 4.18.0-240.10.1.el8_3, bpftool 4.18.0-240.10.1.el8_3, kernel-core 4.18.0-240.10.1.el8_3, kernel-tools 4.18.0-240.10.1.el8_3, python3-perf 4.18.0-240.10.1.el8_3, +15 more
    fixed: vendor fix RHSA-2021:0003
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.1) kernel 4.18.0-147.38.1.el8_1, kernel-core 4.18.0-147.38.1.el8_1, kernel-modules 4.18.0-147.38.1.el8_1, kernel-zfcpdump 4.18.0-147.38.1.el8_1, kpatch-patch-4_18_0-147_8_1 1-8.el8_1, kpatch-patch-4_18_0-147_13_2 1-6.el8_1, +17 more
    fixed: vendor fix RHSA-2021:0184
show 28 more
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) perf 4.18.0-193.46.1.el8_2, kernel 4.18.0-193.46.1.el8_2, bpftool 4.18.0-193.46.1.el8_2, kpatch-patch-4_18_0-193 1-10.el8, kernel-core 4.18.0-193.46.1.el8_2, kernel-tools 4.18.0-193.46.1.el8_2, +26 more
    fixed: vendor fix RHSA-2021:0765
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1160.21.1.el7, kernel 3.10.0-1160.21.1.el7, bpftool 3.10.0-1160.21.1.el7, python-perf 3.10.0-1160.21.1.el7, kernel-tools 3.10.0-1160.21.1.el7, kernel-tools-libs 3.10.0-1160.21.1.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.21.1.el7
    fixed: vendor fix RHSA-2021:0856
  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) perf 3.10.0-1062.49.1.el7, kernel 3.10.0-1062.49.1.el7, bpftool 3.10.0-1062.49.1.el7, python-perf 3.10.0-1062.49.1.el7, kernel-tools 3.10.0-1062.49.1.el7, kernel-tools-libs 3.10.0-1062.49.1.el7, +2 more
    fixed: vendor fix RHSA-2021:1531
  • Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.21.1.el7
    fixed: vendor fix RHSA-2021:0856
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7) kernel-debuginfo-common-x86_64 3.10.0-1062.49.1.el7
    fixed: vendor fix RHSA-2021:1531
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-trace 3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.21.1.rt56.1158.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-kvm 3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-trace 3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-debug-kvm 3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-trace-kvm 3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.21.1.rt56.1158.el7
    fixed: vendor fix RHSA-2021:0857
  • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-core 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-modules 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-debug-core 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-debug-modules 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-modules-extra 4.18.0-240.10.1.rt7.64.el8_3, +2 more
    fixed: vendor fix RHSA-2021:0004
  • Red Hat Enterprise Linux Real Time EUS (v. 8.2) kernel-rt 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-core 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-modules 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-debug-core 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-debug-modules 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-modules-extra 4.18.0-193.46.1.rt13.96.el8_2, +2 more
    fixed: vendor fix RHSA-2021:0774
  • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-kvm 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-core 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-modules 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-debug-kvm 4.18.0-240.10.1.rt7.64.el8_3, kernel-rt-debug-core 4.18.0-240.10.1.rt7.64.el8_3, +4 more
    fixed: vendor fix RHSA-2021:0004
  • Red Hat Enterprise Linux Real Time for NFV EUS (v. 8.2) kernel-rt 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-kvm 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-core 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-modules 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-debug-kvm 4.18.0-193.46.1.rt13.96.el8_2, kernel-rt-debug-core 4.18.0-193.46.1.rt13.96.el8_2, +4 more
    fixed: vendor fix RHSA-2021:0774
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1160.21.1.el7, kernel 3.10.0-1160.21.1.el7, bpftool 3.10.0-1160.21.1.el7, python-perf 3.10.0-1160.21.1.el7, kernel-kdump 3.10.0-1160.21.1.el7, kernel-tools 3.10.0-1160.21.1.el7, +7 more
    fixed: vendor fix RHSA-2021:0856
  • Red Hat Enterprise Linux Server AUS (v. 7.4) perf 3.10.0-693.87.1.el7, kernel 3.10.0-693.87.1.el7, python-perf 3.10.0-693.87.1.el7, kernel-tools 3.10.0-693.87.1.el7, kernel-tools-libs 3.10.0-693.87.1.el7, kernel-abi-whitelists 3.10.0-693.87.1.el7, +1 more
    fixed: vendor fix RHSA-2021:2164
  • Red Hat Enterprise Linux Server AUS (v. 7.6) perf 3.10.0-957.76.1.el7, kernel 3.10.0-957.76.1.el7, bpftool 3.10.0-957.76.1.el7, python-perf 3.10.0-957.76.1.el7, kernel-tools 3.10.0-957.76.1.el7, kernel-tools-libs 3.10.0-957.76.1.el7, +2 more
    fixed: vendor fix RHSA-2021:2355
  • Red Hat Enterprise Linux Server E4S (v. 7.4) perf 3.10.0-693.87.1.el7, kernel 3.10.0-693.87.1.el7, python-perf 3.10.0-693.87.1.el7, kernel-tools 3.10.0-693.87.1.el7, kernel-tools-libs 3.10.0-693.87.1.el7, kernel-bootwrapper 3.10.0-693.87.1.el7, +3 more
    fixed: vendor fix RHSA-2021:2164
  • Red Hat Enterprise Linux Server E4S (v. 7.6) perf 3.10.0-957.76.1.el7, kernel 3.10.0-957.76.1.el7, bpftool 3.10.0-957.76.1.el7, python-perf 3.10.0-957.76.1.el7, kernel-tools 3.10.0-957.76.1.el7, kernel-tools-libs 3.10.0-957.76.1.el7, +4 more
    fixed: vendor fix RHSA-2021:2355
  • Red Hat Enterprise Linux Server EUS (v. 7.7) perf 3.10.0-1062.49.1.el7, kernel 3.10.0-1062.49.1.el7, bpftool 3.10.0-1062.49.1.el7, python-perf 3.10.0-1062.49.1.el7, kernel-kdump 3.10.0-1062.49.1.el7, kernel-tools 3.10.0-1062.49.1.el7, +7 more
    fixed: vendor fix RHSA-2021:1531
  • Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.21.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.21.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.21.1.el7
    fixed: vendor fix RHSA-2021:0856
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.4) kernel-debuginfo-common-x86_64 3.10.0-693.87.1.el7
    fixed: vendor fix RHSA-2021:2164
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.6) kernel-debuginfo-common-x86_64 3.10.0-957.76.1.el7
    fixed: vendor fix RHSA-2021:2355
  • Red Hat Enterprise Linux Server Optional E4S (v. 7.4) kernel-debuginfo-common-x86_64 3.10.0-693.87.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-693.87.1.el7
    fixed: vendor fix RHSA-2021:2164
  • Red Hat Enterprise Linux Server Optional E4S (v. 7.6) kernel-debuginfo-common-x86_64 3.10.0-957.76.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-957.76.1.el7
    fixed: vendor fix RHSA-2021:2355
  • Red Hat Enterprise Linux Server Optional EUS (v. 7.7) kernel-debuginfo-common-ppc64 3.10.0-1062.49.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1062.49.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1062.49.1.el7
    fixed: vendor fix RHSA-2021:1531
  • Red Hat Enterprise Linux Server Optional TUS (v. 7.4) kernel-debuginfo-common-x86_64 3.10.0-693.87.1.el7
    fixed: vendor fix RHSA-2021:2164
  • Red Hat Enterprise Linux Server Optional TUS (v. 7.6) kernel-debuginfo-common-x86_64 3.10.0-957.76.1.el7
    fixed: vendor fix RHSA-2021:2355
  • Red Hat Enterprise Linux Server TUS (v. 7.4) perf 3.10.0-693.87.1.el7, kernel 3.10.0-693.87.1.el7, python-perf 3.10.0-693.87.1.el7, kernel-tools 3.10.0-693.87.1.el7, kernel-tools-libs 3.10.0-693.87.1.el7, kernel-abi-whitelists 3.10.0-693.87.1.el7, +1 more
    fixed: vendor fix RHSA-2021:2164
  • Red Hat Enterprise Linux Server TUS (v. 7.6) perf 3.10.0-957.76.1.el7, kernel 3.10.0-957.76.1.el7, bpftool 3.10.0-957.76.1.el7, python-perf 3.10.0-957.76.1.el7, kernel-tools 3.10.0-957.76.1.el7, kernel-tools-libs 3.10.0-957.76.1.el7, +2 more
    fixed: vendor fix RHSA-2021:2355
  • Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1160.21.1.el7, kernel 3.10.0-1160.21.1.el7, bpftool 3.10.0-1160.21.1.el7, python-perf 3.10.0-1160.21.1.el7, kernel-tools 3.10.0-1160.21.1.el7, kernel-tools-libs 3.10.0-1160.21.1.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.21.1.el7
    fixed: vendor fix RHSA-2021:0856
  • Red Hat CodeReady Linux Builder EUS (v. 8.1) perf-debuginfo 4.18.0-147.38.1.el8_1, bpftool-debuginfo 4.18.0-147.38.1.el8_1, kernel-tools-debuginfo 4.18.0-147.38.1.el8_1, python3-perf-debuginfo 4.18.0-147.38.1.el8_1, kernel-tools-libs-devel 4.18.0-147.38.1.el8_1
    not affected: vulnerable code not present

1 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

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • git.kernel.org https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1cc5ef91d2ff94d2bf2de3b3585423e8a1051cb6 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.0 CVSS:3.1/AV:L/AC:L/PR:H/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-120 Buffer Copy without Checking Size of Input
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.