UBUNTU-CVE-2021-45100

Advisory lineage Upstream: 1 Downstream: 0
Upstream
CVE-2021-45100
Published: 16 Dec 2021, 05:15
Last modified:24 Oct 2025, 04:50

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
3.1 (osv_ubuntu)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

16 Dec 2021, 05:15
Published
Vulnerability first disclosed
24 Oct 2025, 04:50
Last Modified
Vulnerability information updated

Description

The ksmbd server through 3.4.2, as used in the Linux kernel through 5.15.8, sometimes communicates in cleartext even though encryption has been enabled. This occurs because it sets the SMB2_GLOBAL_CAP_ENCRYPTION flag when using the SMB 3.1.1 protocol, which is a violation of the SMB protocol specification. When Windows 10 detects this protocol violation, it disables encryption.

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected Systems

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-azure

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-gcp

    all

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.8

    all

  • ubuntu•linux-gke-4.15

    all

  • ubuntu•linux-hwe

    all

  • ubuntu•linux-hwe-5.11

    all

  • ubuntu•linux-hwe-5.8

    all

  • ubuntu•linux-hwe-edge

    all | all

  • ubuntu•linux-intel-5.13

    all

  • ubuntu•linux-oem

    all

  • ubuntu•linux-oem-5.6

    all

  • ubuntu•linux-oracle-5.0

    all

  • ubuntu•linux-oracle-5.3

    all

  • ubuntu•linux-oracle-5.8

    all

  • ubuntu•linux-raspi2

    all

  • ubuntu•linux-riscv

    all

  • ubuntu•linux-riscv-5.8

    all

References (5)