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Fencer Vulns
medium 5.1

CVE-2020-4788 json

IBM Power9 (AIX 7.1, 7.2, and VIOS 3.1) processors could allow a local user to obtain sensitive information from the data in the L1 cache u…

published 2020-11-20 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-26035

cvss
5.1
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits
0
none known

Summary

IBM Power9 (AIX 7.1, 7.2, and VIOS 3.1) processors could allow a local user to obtain sensitive information from the data in the L1 cache under extenuating circumstances. IBM X-Force ID: 189296.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 5.9.11-1

debian advisories DEBIAN-CVE-2020-4788

  • 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 4.4.0-1119.133
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1032.33
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1032.34
  • linux-hwe Ubuntu 16.04 LTS 4.15.0-126.129~16.04.1
  • linux-kvm Ubuntu 16.04 LTS 4.4.0-1085.94

ubuntu advisories UBUNTU-CVE-2020-4788

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 4.18.0-372.9.1.el8
  • perf RHEL 8 4.18.0-372.9.1.el8
  • bpftool RHEL 8 4.18.0-372.9.1.el8
  • kernel-core RHEL 8 4.18.0-372.9.1.el8
  • kernel-tools RHEL 8 4.18.0-372.9.1.el8
  • python3-perf RHEL 8 4.18.0-372.9.1.el8
  • kernel-modules RHEL 8 4.18.0-372.9.1.el8
  • kernel-zfcpdump RHEL 8 4.18.0-372.9.1.el8

red hat advisories RHSA-2022:1988

  • kernel-syms SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +3 more 4.4.180-94.150.1
  • kernel-source SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +3 more 4.4.180-94.150.1
  • kernel-default SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 4.4.180-94.150.1
  • kgraft-patch-SLE12-SP3_Update_41 SLES for SAP 12 SP3, SLES 12 SP3-LTSS, OpenStack Cloud Crowbar 8 +2 more 1-4.3.1
  • kernel-syms SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +3 more 4.12.14-197.102.2
  • kernel-source SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +3 more 4.12.14-197.102.2
  • kernel-default SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +5 more 4.12.14-197.102.2
  • kernel-obs-build SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +3 more 4.12.14-197.102.1

suse advisories SUSE-SU-2021:3935-1SUSE-SU-2021:3876-1SUSE-SU-2021:14630-1SUSE-SU-2021:0452-1SUSE-SU-2021:0438-1SUSE-SU-2021:0434-1

  • kernel-default openSUSE Leap 15.3 4.12.14-197.102.2
  • kernel-vanilla openSUSE Leap 15.3 4.12.14-197.102.2
  • kernel-kvmsmall openSUSE Leap 15.3 4.12.14-197.102.2
  • kernel-zfcpdump openSUSE Leap 15.3 4.12.14-197.102.2
  • 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

opensuse advisories openSUSE-SU-2021:3876-1openSUSE-SU-2021:0242-1openSUSE-SU-2021:0075-1openSUSE-SU-2020:2260-1openSUSE-SU-2020:2193-1openSUSE-SU-2020:2161-1

  • kernel AlmaLinux 8 4.18.0-372.9.1.el8
  • perf AlmaLinux 8 4.18.0-372.9.1.el8
  • bpftool AlmaLinux 8 4.18.0-372.9.1.el8
  • kernel-core AlmaLinux 8 4.18.0-372.9.1.el8
  • kernel-tools AlmaLinux 8 4.18.0-372.9.1.el8
  • python3-perf AlmaLinux 8 4.18.0-372.9.1.el8
  • kernel-modules AlmaLinux 8 4.18.0-372.9.1.el8
  • kernel-debug-core AlmaLinux 8 4.18.0-372.9.1.el8

almalinux advisories ALSA-2022:1988

  • kernel Rocky Linux 8 4.18.0-372.9.1.el8

rocky linux advisories RLSA-2022:1988

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-2020-4788 updated cvss 5.1

kernel: speculation on incompletely validated data on IBM Power9

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-alt, python-perf, kernel-kdump, +4 more
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-372.9.1.el8, kernel 4.18.0-372.9.1.el8, bpftool 4.18.0-372.9.1.el8, kernel-core 4.18.0-372.9.1.el8, kernel-tools 4.18.0-372.9.1.el8, python3-perf 4.18.0-372.9.1.el8, +15 more Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-372.9.1.el8, kernel-debuginfo-common-aarch64 4.18.0-372.9.1.el8, kernel-debuginfo-common-ppc64le 4.18.0-372.9.1.el8
    fixed: vendor fix RHSA-2022:1988
  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 kernel-rt, kernel-rt-kvm, kernel-rt-trace, kernel-rt-debug-kvm, kernel-rt-trace-kvm Red Hat Enterprise Linux 8 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +6 more Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    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

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.0 5.1 CVSS:3.0/PR:N/C:H/AV:L/AC:H/S:U/A:N/I:N/UI:N/E:U/RC:C/RL:O
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
CNA 3.0 5.1 CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 1.9 AV:L/AC:M/Au:N/C:P/I:N/A:N

Affected products

  • IBM VIOS
  • IBM AIX

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.