synced 10 MIN AGO
01 Record

CVE-2020-36557

A race condition in the Linux kernel before 5.6.2 between the VT_DISALLOCATE ioctl and closing/opening of ttys could lead to a use-after-free.

UnratedPUBLISHEDCNA: mitre
CNA base scoreUnratedNo CNA CVSS vector

02 Description

A race condition in the Linux kernel before 5.6.2 between the VT_DISALLOCATE ioctl and closing/opening of ttys could lead to a use-after-free.

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
0.20% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 9.9% of scored records. A rank, not a probability.
NVD base score
5.1 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:L/AC:H/PR:N/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
2022-07-21 03:46Z4 YR AGO
Last updated
2024-08-04 17:30Z2 YR AGO
Reserved
2022-07-21
Assigning CNA
mitre
Record state
PUBLISHED
Severity
Not rated by the issuing CNA
CNA CVSS vector
Not published by the issuing CNA
Weaknesses
  • CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')Class
  • CWE-416Use After FreeVariant
Data version
5.1
Document digest
2a6c9117d0c9a98cbf75e4096d593d84ff96d07e6f7badf1ad7b785e31f71e14

05 Affected products

VendorProductVersionsPlatforms
linuxlinux_kernelNot specified—
redhatenterprise_linuxNot specified—

06 References

07 Fixed in

Debian 12

  • linux
    Fixed in 5.5.17-1

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

Debian 13

  • linux
    Fixed in 5.5.17-1

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

Debian 14

  • linux
    Fixed in 5.5.17-1

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

Ubuntu 16.04 LTS

  • linux
    Fixed in 4.4.0-179.209
  • linux-aws
    Fixed in 4.4.0-1107.118
  • linux-aws-hwe
    Fixed in 4.15.0-1066.70~16.04.1
  • linux-azure
    Fixed in 4.15.0-1082.92~16.04.1
  • linux-gcp
    Fixed in 4.15.0-1061.65
  • linux-hwe
    Fixed in 4.15.0-99.100~16.04.1
  • linux-hwe-edge
    No fix yet
  • linux-kvm
    Fixed in 4.4.0-1071.78
  • linux-oracle
    Fixed in 4.15.0-1038.42~16.04.1

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 4.15.0-99.100
  • linux-aws
    Fixed in 4.15.0-1066.70
  • linux-aws-5.0
    No fix yet
  • linux-aws-5.3
    No fix yet
  • linux-azure
    No fix yet
  • linux-azure-5.3
    No fix yet
  • linux-azure-edge
    No fix yet
  • linux-gcp
    No fix yet
  • linux-gcp-5.3
    No fix yet
  • linux-gke-4.15
    No fix yet
  • linux-gke-5.4
    No fix yet
  • linux-gkeop-5.4
    No fix yet
  • linux-hwe
    No fix yet
  • linux-hwe-edge
    No fix yet
  • linux-kvm
    Fixed in 4.15.0-1059.60
  • linux-oem
    No fix yet
  • linux-oem-osp1
    Fixed in 5.0.0-1052.57
  • linux-oracle
    Fixed in 4.15.0-1038.42
  • linux-oracle-5.0
    No fix yet
  • linux-oracle-5.3
    No fix yet
  • linux-raspi2
    Fixed in 4.15.0-1061.65
  • linux-snapdragon
    Fixed in 4.15.0-1077.84

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-5.11
    No fix yet
  • linux-aws-5.13
    No fix yet
  • linux-aws-5.8
    No fix yet
  • linux-azure-5.11
    No fix yet
  • linux-azure-5.13
    No fix yet
  • linux-azure-5.8
    No fix yet
  • linux-gcp-5.11
    No fix yet
  • linux-gcp-5.13
    No fix yet
  • linux-gcp-5.8
    No fix yet
  • linux-hwe-5.11
    No fix yet
  • linux-hwe-5.13
    No fix yet
  • linux-hwe-5.8
    No fix yet
  • linux-intel-5.13
    No fix yet
  • linux-oem-5.10
    No fix yet
  • linux-oem-5.13
    No fix yet
  • linux-oem-5.6
    No fix yet
  • linux-oracle-5.11
    No fix yet
  • linux-oracle-5.13
    No fix yet
  • linux-oracle-5.8
    No fix yet
  • linux-raspi
    Fixed in 5.4.0-1011.11
  • linux-raspi2
    No fix yet
  • linux-riscv
    No fix yet
  • linux-riscv-5.11
    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 4.4.0-1067.71
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-azure
    Fixed in 4.15.0-1082.92~14.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-lts-xenial
    Fixed in 4.4.0-179.209~14.04.1
    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 FIPS-updates 16.04 LTS

  • linux-fips
    Fixed in 4.4.0-1034.39
    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 4.15.0-2018.18
    Available with Ubuntu Pro: https://ubuntu.com/pro
  • linux-azure-fips
    Fixed in 4.15.0-2006.7
    Available with Ubuntu Pro: https://ubuntu.com/pro
  • linux-fips
    Fixed in 4.15.0-1029.34
    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-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.