CVE-2021-45100: Ksmbd Project Ksmbd

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

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.

Affected products

• Ksmbd Project Ksmbd: up to and including 3.4.2
• Netapp h300e Firmware: affected versions not specified
• Netapp h300s Firmware: affected versions not specified
• Netapp h410c Firmware: affected versions not specified
• Netapp h410s Firmware: affected versions not specified
• Netapp h500e Firmware: affected versions not specified
• Netapp h500s Firmware: affected versions not specified
• Netapp h700e Firmware: affected versions not specified
• Netapp h700s Firmware: affected versions not specified

Published 2021-12-16. Last modified 2026-06-17.