CVE-2021-33624

Aliases:UBUNTU-CVE-2021-33624DEBIAN-CVE-2021-33624
Advisory lineage Upstream: 0 Downstream: 24
Modified
Published: 23 Jun 2021, 15:37
Last modified:11 Nov 2025, 15:19

Vulnerability Summary

Overall Risk (default)
medium
29/100
CVSS Score
4.7 MEDIUM
v3.1 (nvd)
EPSS Score
0.92% LOW
1% probability +0.45%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

23 Jun 2021, 15:37
Published
Vulnerability first disclosed
11 Nov 2025, 15:19
Last Modified
Vulnerability information updated

Description

In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db.

CVSS Metrics

  • v3.1•MEDIUM•Score: 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
  • v2.0•MEDIUM•Score: 4.7AV:L/AC:M/Au:N/C:C/I:N/A:N

EPSS Trends

Current EPSS score: 0.92%• Percentile: 59%

Techniques & Countermeasures

  • CWE-843•Access of Resource Using Incompatible Type ('Type Confusion')

    The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

Affected Systems

  • debian•linux

    < 5.10.46-1 | < 5.10.46-1 | < 5.10.46-1 | < 5.10.46-1

  • ubuntu•linux

    all | < 5.4.0-88.99

  • ubuntu•linux-aws

    all | < 5.4.0-1057.60

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    < 5.11.0-1019.20~20.04.1

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    < 5.4.0-1057.60~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-fips

    all | < 5.4.0-1069.73+fips2

  • ubuntu•linux-aws-hwe

    all

  • ubuntu•linux-azure

    all | all | < 5.4.0-1059.62

  • ubuntu•linux-azure-4.15

    all

  • ubuntu•linux-azure-5.11

    < 5.11.0-1017.18~20.04.1

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    < 5.4.0-1059.62~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fips

    all | < 5.4.0-1073.76+fips1

  • ubuntu•linux-bluefield

    all | < 5.4.0-1019.22

  • ubuntu•linux-fips

    all | < 5.4.0-1034.40

  • ubuntu•linux-gcp

    all | all | < 5.4.0-1053.57

  • ubuntu•linux-gcp-4.15

    all

  • ubuntu•linux-gcp-5.11

    < 5.11.0-1020.22~20.04.1

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.4

    < 5.4.0-1053.57~18.04.1

  • ubuntu•linux-gcp-5.8

    all

  • ubuntu•linux-gcp-edge

    all

  • ubuntu•linux-gcp-fips

    all | < 5.4.0-1067.71~20.04.1

  • ubuntu•linux-gke

    < 5.4.0-1053.56

  • ubuntu•linux-gke-4.15

    all

  • ubuntu•linux-gke-5.4

    < 5.4.0-1053.56~18.04.1

  • ubuntu•linux-gkeop

    < 5.4.0-1024.25

  • ubuntu•linux-gkeop-5.4

    < 5.4.0-1024.25~18.04.1

  • ubuntu•linux-hwe

    all | all

  • ubuntu•linux-hwe-5.11

    < 5.11.0-37.41~20.04.2

  • ubuntu•linux-hwe-5.4

    < 5.4.0-87.98~18.04.1

  • ubuntu•linux-hwe-5.8

    all

  • ubuntu•linux-hwe-edge

    all | all

  • ubuntu•linux-ibm

    < 5.4.0-1005.6

  • ubuntu•linux-intel-iot-realtime

    all

  • ubuntu•linux-kvm

    all | < 5.4.0-1047.49

  • ubuntu•linux-lts-xenial

    all

  • ubuntu•linux-oem

    all

  • ubuntu•linux-oem-5.10

    < 5.10.0-1050.52

  • ubuntu•linux-oem-5.6

    all

  • ubuntu•linux-oracle

    all | < 5.4.0-1055.59

  • ubuntu•linux-oracle-5.0

    all

  • ubuntu•linux-oracle-5.11

    < 5.11.0-1019.20~20.04.1

  • ubuntu•linux-oracle-5.3

    all

  • ubuntu•linux-oracle-5.4

    < 5.4.0-1055.59~18.04.1

Showing first 50 affected entries in server-rendered view.

References (18)