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Fencer Vulns
medium 6.7

CVE-2020-15436 json

Use-after-free vulnerability in fs/block_dev.c in the Linux kernel before 5.8 allows local users to gain privileges or cause a denial of se…

published 2020-11-23 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-7429

cvss
6.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 60%
public exploits
0
none known

Summary

Use-after-free vulnerability in fs/block_dev.c in the Linux kernel before 5.8 allows local users to gain privileges or cause a denial of service by leveraging improper access to a certain error field.

Patch / fix

  • linux linux_kernel 4.4.229, 4.9.229, 4.14.186, 4.19.130, 5.4.49, 5.7.6
  • linux Debian 14, Debian 13, Debian 12 5.7.6-1

debian advisories DEBIAN-CVE-2020-15436

  • linux Ubuntu 16.04 LTS 4.4.0-187.217
  • linux Ubuntu 18.04 LTS 4.15.0-115.116
  • linux Ubuntu 20.04 LTS 5.4.0-45.49
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1112.124
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1080.84
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1022.22
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1081.92~16.04.1
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1022.22

ubuntu advisories UBUNTU-CVE-2020-15436

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

  • perf RHEL 7.6 EUS, RHEL 7 3.10.0-957.72.1.el7
  • python-perf RHEL 7.6 EUS, RHEL 7 3.10.0-957.72.1.el7
  • kernel RHEL 7 3.10.0-1160.15.2.el7
  • perf RHEL 7 3.10.0-1160.15.2.el7
  • bpftool RHEL 7 3.10.0-1160.15.2.el7
  • python-perf RHEL 7 3.10.0-1160.15.2.el7
  • kernel-kdump RHEL 7 3.10.0-1160.15.2.el7
  • kernel-tools RHEL 7 3.10.0-1160.15.2.el7

red hat advisories RHSA-2021:2523RHSA-2021:1376RHSA-2021:0336RHSA-2021:0338RHSA-2021:0354

  • 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-2021:0098-1

  • 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 15.1 4.12.14-lp151.28.87.1
  • kernel-obs-qa openSUSE Leap 15.1 4.12.14-lp151.28.87.2
  • kernel-source openSUSE Leap 15.1 4.12.14-lp151.28.87.1

opensuse advisories openSUSE-SU-2021:0242-1openSUSE-SU-2020:2260-1openSUSE-SU-2020:2193-1openSUSE-SU-2020:2161-1

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-2020-15436 updated cvss 6.7

kernel: use-after-free in fs/block_dev.c

  • 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 MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1160.15.2.el7, kernel 3.10.0-1160.15.2.el7, bpftool 3.10.0-1160.15.2.el7, python-perf 3.10.0-1160.15.2.el7, kernel-tools 3.10.0-1160.15.2.el7, kernel-tools-libs 3.10.0-1160.15.2.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.15.2.el7
    fixed: vendor fix RHSA-2021:0336
  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.6) perf 3.10.0-957.72.1.el7, kernel 3.10.0-957.72.1.el7, bpftool 3.10.0-957.72.1.el7, python-perf 3.10.0-957.72.1.el7, kernel-tools 3.10.0-957.72.1.el7, kernel-tools-libs 3.10.0-957.72.1.el7, +2 more
    fixed: vendor fix RHSA-2021:1376
  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) perf 3.10.0-1062.51.1.el7, kernel 3.10.0-1062.51.1.el7, bpftool 3.10.0-1062.51.1.el7, python-perf 3.10.0-1062.51.1.el7, kernel-tools 3.10.0-1062.51.1.el7, kernel-tools-libs 3.10.0-1062.51.1.el7, +2 more
    fixed: vendor fix RHSA-2021:2523
  • Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.15.2.el7
    fixed: vendor fix RHSA-2021:0336
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6) kernel-debuginfo-common-x86_64 3.10.0-957.72.1.el7
    fixed: vendor fix RHSA-2021:1376
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7) kernel-debuginfo-common-x86_64 3.10.0-1062.51.1.el7
    fixed: vendor fix RHSA-2021:2523
show 11 more
  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) perf 4.14.0-115.35.1.el7a, kernel 4.14.0-115.35.1.el7a, kernel-alt 4.14.0-115.35.1.el7a, python-perf 4.14.0-115.35.1.el7a, kernel-tools 4.14.0-115.35.1.el7a, kernel-tools-libs 4.14.0-115.35.1.el7a, +3 more Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) kernel-debuginfo-common-ppc64le 4.14.0-115.35.1.el7a
    fixed: vendor fix RHSA-2021:0354
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1160.15.2.rt56.1152.el7, kernel-rt-trace 3.10.0-1160.15.2.rt56.1152.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.15.2.rt56.1152.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1160.15.2.rt56.1152.el7, kernel-rt-kvm 3.10.0-1160.15.2.rt56.1152.el7, kernel-rt-trace 3.10.0-1160.15.2.rt56.1152.el7, kernel-rt-debug-kvm 3.10.0-1160.15.2.rt56.1152.el7, kernel-rt-trace-kvm 3.10.0-1160.15.2.rt56.1152.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.15.2.rt56.1152.el7
    fixed: vendor fix RHSA-2021:0338
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1160.15.2.el7, kernel 3.10.0-1160.15.2.el7, bpftool 3.10.0-1160.15.2.el7, python-perf 3.10.0-1160.15.2.el7, kernel-kdump 3.10.0-1160.15.2.el7, kernel-tools 3.10.0-1160.15.2.el7, +7 more
    fixed: vendor fix RHSA-2021:0336
  • Red Hat Enterprise Linux Server EUS (v. 7.6) perf 3.10.0-957.72.1.el7, kernel 3.10.0-957.72.1.el7, bpftool 3.10.0-957.72.1.el7, python-perf 3.10.0-957.72.1.el7, kernel-kdump 3.10.0-957.72.1.el7, kernel-tools 3.10.0-957.72.1.el7, +7 more
    fixed: vendor fix RHSA-2021:1376
  • Red Hat Enterprise Linux Server EUS (v. 7.7) perf 3.10.0-1062.51.1.el7, kernel 3.10.0-1062.51.1.el7, bpftool 3.10.0-1062.51.1.el7, python-perf 3.10.0-1062.51.1.el7, kernel-kdump 3.10.0-1062.51.1.el7, kernel-tools 3.10.0-1062.51.1.el7, +7 more
    fixed: vendor fix RHSA-2021:2523
  • Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.15.2.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.15.2.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.15.2.el7
    fixed: vendor fix RHSA-2021:0336
  • Red Hat Enterprise Linux Server Optional EUS (v. 7.6) kernel-debuginfo-common-ppc64 3.10.0-957.72.1.el7, kernel-debuginfo-common-x86_64 3.10.0-957.72.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-957.72.1.el7
    fixed: vendor fix RHSA-2021:1376
  • Red Hat Enterprise Linux Server Optional EUS (v. 7.7) kernel-debuginfo-common-ppc64 3.10.0-1062.51.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1062.51.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1062.51.1.el7
    fixed: vendor fix RHSA-2021:2523
  • Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1160.15.2.el7, kernel 3.10.0-1160.15.2.el7, bpftool 3.10.0-1160.15.2.el7, python-perf 3.10.0-1160.15.2.el7, kernel-tools 3.10.0-1160.15.2.el7, kernel-tools-libs 3.10.0-1160.15.2.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.15.2.el7
    fixed: vendor fix RHSA-2021:0336
  • Red Hat Virtualization 4.2 Hypervisor for RHEL 7.6 EUS perf 3.10.0-957.72.1.el7, python-perf 3.10.0-957.72.1.el7
    fixed: vendor fix RHSA-2021:1376
  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux Client (v. 7) kernel-headers 3.10.0-1160.15.2.el7 Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) kernel-headers 3.10.0-1062.51.1.el7 Red Hat Enterprise Linux Server (v. 7) kernel-headers 3.10.0-1160.15.2.el7 Red Hat Enterprise Linux Server EUS (v. 7.7) kernel-headers 3.10.0-1062.51.1.el7
    +1 more products
    Red Hat Enterprise Linux Workstation (v. 7) kernel-headers 3.10.0-1160.15.2.el7
    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

cisa ICSA-24-074-07 updated cvss 6.7

Siemens SIMATIC

  • Siemens SIMATIC RF160B (6GT2003-0FA00) <V2.2
    affected: mitigation “Siemens has released a new version (V2.2) for SIMATIC RF160B and recommends to update to the latest version.” siemens.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

0.93% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • lkml.org https://lkml.org/lkml/2020/6/7/379 referenced PoC, tagged "exploit" by a source, unverified

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 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.