7.5

CVE-2021-45100: ksmbd_project ksmbd

Modified
AliasesUBUNTU-CVE-2021-45100DEBIAN-CVE-2021-45100
Published 16-12-2021Last modified 04-08-2024

Vulnerability summary

CVE-2021-45100 is a high (CVSS 7.5) vulnerability in ksmbd_project ksmbd. EPSS estimates a 0.91% chance of exploitation in the next 30 days, higher than 60% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (NVD); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
0.91%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2
MGASA-2022-0021MGASA-2022-0022

Timeline

  1. 16-12-2021
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability 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

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.91%

Chance of exploitation in the next 30 days

Percentile

60%

Versus all other CVEs

30-day change

Increase +0.03 pp

From 0.88% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu24 products
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.3All versions (No fix recorded)
  • linux-aws-5.8All versions (No fix recorded)
  • linux-azureAll versions (No fix recorded)
  • linux-azure-5.3All versions (No fix recorded)
Netapp8 products
Debian1 product
  • linux< 5.15.15-1
Ksmbd_project1 product

4 vendors · 34 products

References

7 links