UBUNTU-CVE-2021-33909

Advisory lineage Upstream: 1 Downstream: 8
Upstream
CVE-2021-33909
Published: 20 Jul 2021, 12:00
Last modified:20 May 2026, 16:05

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
3.1 (osv_ubuntu)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

20 Jul 2021, 12:00
Published
Vulnerability first disclosed
20 May 2026, 16:05
Last Modified
Vulnerability information updated

Description

fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd89f05.

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Systems

  • ubuntu•linux

    < 3.13.0-186.237 | < 4.4.0-212.244 | < 4.15.0-151.157 | < 5.4.0-80.90

  • ubuntu•linux-aws

    < 4.4.0-1094.99 | < 4.4.0-1130.144 | < 4.15.0-1109.116 | < 5.4.0-1054.57

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    < 5.11.0-1014.15~20.04.1

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    < 5.4.0-1054.57~18.04.1

  • ubuntu•linux-aws-5.8

    < 5.8.0-1041.43~20.04.1

  • ubuntu•linux-aws-fips

    < 4.15.0-2051.53 | all | < 5.4.0-1069.73+fips2

  • ubuntu•linux-aws-hwe

    < 4.15.0-1109.116~16.04.1

  • ubuntu•linux-azure

    < 4.15.0-1121.134~14.04.1 | < 4.15.0-1121.134~16.04.1 | all | < 5.4.0-1055.57

  • ubuntu•linux-azure-4.15

    < 4.15.0-1121.134

  • ubuntu•linux-azure-5.11

    < 5.11.0-1012.13~20.04.1

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    < 5.4.0-1055.57~18.04.1

  • ubuntu•linux-azure-5.8

    < 5.8.0-1039.42~20.04.1

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fips

    < 4.15.0-2033.37 | all | < 5.4.0-1073.76+fips1

  • ubuntu•linux-bluefield

    < 5.4.0-1016.19

  • ubuntu•linux-dell300x

    < 4.15.0-1027.32

  • ubuntu•linux-fips

    < 4.4.0-1064.70 | all | < 4.15.0-1066.75 | < 5.4.0-1031.36

  • ubuntu•linux-gcp

    < 4.15.0-1106.120~16.04.1 | all | < 5.4.0-1049.53

  • ubuntu•linux-gcp-4.15

    < 4.15.0-1106.120

  • ubuntu•linux-gcp-5.11

    < 5.11.0-1014.16~20.04.1

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.4

    < 5.4.0-1049.53~18.04.1

  • ubuntu•linux-gcp-5.8

    < 5.8.0-1038.40~20.04.1

  • ubuntu•linux-gcp-edge

    all

  • ubuntu•linux-gcp-fips

    < 4.15.0-2016.18 | all | < 5.4.0-1067.71~20.04.1

  • ubuntu•linux-gke

    < 5.4.0-1049.52

  • ubuntu•linux-gke-4.15

    all

  • ubuntu•linux-gke-5.3

    < 5.3.0-1045.48

  • ubuntu•linux-gke-5.4

    < 5.4.0-1049.52~18.04.1

  • ubuntu•linux-gkeop

    < 5.4.0-1021.22

  • ubuntu•linux-gkeop-5.4

    < 5.4.0-1021.22~18.04.1

  • ubuntu•linux-hwe

    < 4.15.0-151.157~16.04.1 | < 5.3.0-76.72

  • ubuntu•linux-hwe-5.11

    < 5.11.0-25.27~20.04.1

  • ubuntu•linux-hwe-5.4

    < 5.4.0-80.90~18.04.1

  • ubuntu•linux-hwe-5.8

    < 5.8.0-63.71~20.04.1

  • ubuntu•linux-hwe-edge

    all | all

  • ubuntu•linux-intel-iot-realtime

    all

  • ubuntu•linux-kvm

    < 4.4.0-1095.104 | < 4.15.0-1097.99 | < 5.4.0-1044.46

  • ubuntu•linux-lts-xenial

    < 4.4.0-212.244~14.04.1

  • ubuntu•linux-nvidia

    all

  • ubuntu•linux-oem

    all

  • ubuntu•linux-oem-5.10

    < 5.10.0-1038.40

  • ubuntu•linux-oem-5.6

    all

  • ubuntu•linux-oracle

    < 4.15.0-1078.86~16.04.1 | < 4.15.0-1078.86 | < 5.4.0-1052.56

  • ubuntu•linux-oracle-5.0

    all

  • ubuntu•linux-oracle-5.11

    < 5.11.0-1013.14~20.04.1

  • ubuntu•linux-oracle-5.3

    all

Showing first 50 affected entries in server-rendered view.

References (10)