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Fencer Vulns
high 7.8

CVE-2020-25669 json

A vulnerability was found in the Linux Kernel where the function sunkbd_reinit having been scheduled by sunkbd_interrupt before sunkbd bein…

published 2021-05-26 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-18331

cvss
7.8
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 50%
public exploits
0
none known

Summary

A vulnerability was found in the Linux Kernel where the function sunkbd_reinit having been scheduled by sunkbd_interrupt before sunkbd being freed. Though the dangling pointer is set to NULL in sunkbd_disconnect, there is still an alias in sunkbd_reinit causing Use After Free.

Patch / fix

  • linux linux_kernel 4.4.245, 4.9.245, 4.14.208, 4.19.159, 5.4.79, 5.9.10
  • linux Debian 14, Debian 13, Debian 12 5.9.11-1

debian advisories DEBIAN-CVE-2020-25669

  • linux Ubuntu 16.04 LTS 4.4.0-201.233
  • linux Ubuntu 18.04 LTS 4.15.0-136.140
  • linux Ubuntu 20.04 LTS 5.4.0-66.74
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1121.135
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1094.101
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1038.40
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1093.106~16.04.1
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1037.40

ubuntu advisories UBUNTU-CVE-2020-25669

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-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-2020:3798-1

  • kernel-rt openSUSE Leap 15.2 5.3.18-lp152.3.5.1
  • kernel-syms-rt openSUSE Leap 15.2 5.3.18-lp152.3.5.1
  • kernel-rt_debug openSUSE Leap 15.2 5.3.18-lp152.3.5.1
  • kernel-source-rt openSUSE Leap 15.2 5.3.18-lp152.3.5.1
  • kernel-default-base openSUSE Leap 15.2 5.3.18-lp152.57.1.lp152.8.17.1
  • kernel-syms openSUSE Leap 15.2 5.3.18-lp152.54.1
  • kernel-obs-qa openSUSE Leap 15.2 5.3.18-lp152.54.1
  • kernel-source openSUSE Leap 15.2 5.3.18-lp152.54.1

opensuse advisories openSUSE-SU-2021:0242-1openSUSE-SU-2020:2260-1openSUSE-SU-2020:2161-1openSUSE-SU-2020:2034-1

  • linux Arch Linux 5.9.10.arch1-1

arch linux advisories AVG-1314

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-2020-25669 updated cvss 4.1

kernel: use-after-free read in sunkbd_reinit in drivers/input/keyboard/sunkbd.c

  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-core, kernel-tools, python3-perf, +17 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

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • openwall.com http://www.openwall.com/lists/oss-security/2020/11/05/2 referenced PoC, tagged "exploit" by a source, unverified
  • openwall.com http://www.openwall.com/lists/oss-security/2020/11/20/5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 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

Affected products

  • n/a Linux 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.