CVE-2021-21959
A misconfiguration exists in the MQTTS functionality of Sealevel Systems, Inc. SeaConnect 370W v1...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2021-21959- CVSS 3.0
- 7.7 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H - Weakness
- CWE-295
- Updated
- 2026-11-02
EUVDEUVD-2021-9130
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.
- Record
EUVD-2021-9130- CVSS 3.0
- 7.7 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-86q7-w6v5-827g
A misconfiguration exists in the MQTTS functionality of Sealevel Systems, Inc. SeaConnect 370W v1...
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.
- Record
GHSA-86q7-w6v5-827g- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-295
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-21959- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 7.7 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-295
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-21959 is a high vulnerability (CVSS 7.7) in Sealevel Seaconnect 370w Firmware, published February 4, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.84%, the 58th percentile. No source names a fixed version.