CVE-2021-21959

mediumpriority · track · 32EPSS 0.008 · 58 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.84% (58th) EPSS

CVSS 6.8 · medium

Is it mine?

2 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

A misconfiguration exists in the MQTTS functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. This misconfiguration significantly simplifies a man-in-the-middle attack, which directly leads to control of device functionality.

cvss

Technical severity, 0–10. One row per scoring source.

8.1

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.8–8.1

v2.06.8mediumAV:N/AC:M/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 6.4

v3.18.1highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.2 · impact 5.9

v3.07.7highCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:Hsecondary · ENISA EU

v3.07.7highCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:Hsecondary · talos-cna@cisco.com USexploitability 2.2 · impact 5.5

v3.17.4highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: no · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-295USprimary

affected products (2)

Products and version ranges known to be affected.

n/a Sealevel≤ Sealevel Systems, Inc. SeaConnect 370W v1.3.34enisa_euvdEU
sealevel seaconnect 370w firmware= 1.3.34nvdUScpe:2.3:o:sealevel:seaconnect_370w_firmware:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2022-02-04modified 2026-06-17

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references (5)

External citations — patches, advisories, analysis.

scry

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