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.
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
- Data version
- 5.1
- Document digest
- 2a6c9117d0c9a98cbf75e4096d593d84ff96d07e6f7badf1ad7b785e31f71e14
05 Affected products
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 4.4.0-1067.71Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-azure Fixed in 4.15.0-1082.92~14.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-lts-xenial Fixed in 4.4.0-179.209~14.04.1Available 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 4.4.0-1034.39Available 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 4.15.0-2018.18Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-azure-fips Fixed in 4.15.0-2006.7Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-fips Fixed in 4.15.0-1029.34Available 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.