synced 1 MIN AGO
01 Record

CVE-2021-20317

A flaw was found in the Linux kernel. A corrupted timer tree caused the task wakeup to be missing in the timerqueue_add function in lib/timerqueue.c. This flaw allows a local attacker with special

UnratedPUBLISHEDCNA: redhat
CNA base scoreUnratedNo CNA CVSS vector
View raw JSON

02 Description

A flaw was found in the Linux kernel. A corrupted timer tree caused the task wakeup to be missing in the timerqueue_add function in lib/timerqueue.c. This flaw allows a local attacker with special

03 Exploitation and scoring

Exploitation
Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
SSVC decision
Not assessed by CISA
EPSS probability
0.38% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 31.9% of scored records. A rank, not a probability.
NVD base score
4.4 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2021-09-27 10:34Z5 YR AGO
Last updated
2024-08-03 17:37Z2 YR AGO
Reserved
2020-12-17
Assigning CNA
redhat
Record state
PUBLISHED
Severity
Not rated by the issuing CNA
CNA CVSS vector
Not published by the issuing CNA
Weaknesses
  • CWE-665Improper InitializationClass
Data version
5.1
Document digest
4ac254ee8539b43c6aea0e384e1e80e218981b04ba7c78877b4ebcfdc0a8112d

05 Affected products

VendorProductVersionsPlatforms
n/akernelKernel 5.3 rc1—

06 References

07 Fixed in

AlmaLinux 8

  • kernel-tools-libs-devel
    Fixed in 4.18.0-348.2.1.el8_5

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 8

  • kernel-tools-libs-devel
    Fixed in 4.18.0-348.2.1.el8_5

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • linux
    Fixed in 5.4.6-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • linux
    Fixed in 5.4.6-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • linux
    Fixed in 5.4.6-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 16.04 LTS

  • linux-hwe-edge
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 18.04 LTS

  • linux
    Fixed in 4.15.0-166.174
  • linux-aws
    Fixed in 4.15.0-1118.125
  • linux-aws-5.0
    No fix yet
  • linux-aws-5.3
    No fix yet
  • linux-azure
    No fix yet
  • linux-azure-4.15
    Fixed in 4.15.0-1129.142
  • linux-azure-5.3
    No fix yet
  • linux-azure-edge
    No fix yet
  • linux-dell300x
    Fixed in 4.15.0-1033.38
  • linux-gcp
    No fix yet
  • linux-gcp-4.15
    Fixed in 4.15.0-1114.128
  • linux-gcp-5.3
    No fix yet
  • linux-gcp-edge
    No fix yet
  • linux-gke-4.15
    No fix yet
  • linux-hwe
    No fix yet
  • linux-hwe-edge
    No fix yet
  • linux-kvm
    Fixed in 4.15.0-1105.107
  • linux-oem
    No fix yet
  • linux-oracle
    Fixed in 4.15.0-1085.93
  • linux-oracle-5.0
    No fix yet
  • linux-oracle-5.3
    No fix yet
  • linux-raspi2
    Fixed in 4.15.0-1101.108
  • linux-snapdragon
    Fixed in 4.15.0-1118.127

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • linux-aws-5.8
    No fix yet
  • linux-gcp-5.8
    No fix yet
  • linux-oem-5.6
    No fix yet
  • linux-oracle-5.8
    No fix yet
  • linux-raspi2
    No fix yet
  • linux-riscv
    No fix yet
  • linux-riscv-5.8
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • linux-intel-iot-realtime
    No fix yet
  • linux-realtime
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 24.04 LTS

  • linux-raspi-realtime
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 14.04 LTS

  • linux
    No fix yet
  • linux-aws
    Fixed in 4.4.0-1102.107
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-azure
    Fixed in 4.15.0-1129.142~14.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-lts-xenial
    Fixed in 4.4.0-222.255~14.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 16.04 LTS

  • linux
    Fixed in 4.4.0-222.255
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-aws
    Fixed in 4.4.0-1138.152
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-aws-hwe
    Fixed in 4.15.0-1118.125~16.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-azure
    Fixed in 4.15.0-1129.142~16.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-gcp
    Fixed in 4.15.0-1114.128~16.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-hwe
    Fixed in 4.15.0-166.174~16.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-kvm
    Fixed in 4.4.0-1103.112
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-oracle
    Fixed in 4.15.0-1085.93~16.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 20.04 LTS

  • linux-azure-fde-5.15
    Fixed in 5.15.0-1114.123~20.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS-updates 16.04 LTS

  • linux-fips
    Fixed in 4.4.0-1072.78
    Available with Ubuntu Pro: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS-updates 18.04 LTS

  • linux-aws-fips
    Fixed in 4.15.0-2059.61
    Available with Ubuntu Pro: https://ubuntu.com/pro
  • linux-azure-fips
    Fixed in 4.15.0-2041.45
    Available with Ubuntu Pro: https://ubuntu.com/pro
  • linux-fips
    Fixed in 4.15.0-1075.84
    Available with Ubuntu Pro: https://ubuntu.com/pro
  • linux-gcp-fips
    Fixed in 4.15.0-2024.26
    Available with Ubuntu Pro: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS 16.04 LTS

  • linux-fips
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS 18.04 LTS

  • linux-aws-fips
    No fix yet
  • linux-azure-fips
    No fix yet
  • linux-fips
    No fix yet
  • linux-gcp-fips
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.