CVE-2021-21968
A file write vulnerability exists in the OTA update task functionality of Sealevel Systems, Inc....
A file write vulnerability exists in the OTA update task functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to arbitrary file overwrite. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
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
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
A file write vulnerability exists in the OTA update task functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to arbitrary file overwrite. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
- Record
CVE-2021-21968- CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2021-9139
A file write vulnerability exists in the OTA update task functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to arbitrary file overwrite. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
- Record
EUVD-2021-9139- CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-fmc6-6r82-9j7v
A file write vulnerability exists in the OTA update task functionality of Sealevel Systems, Inc....
A file write vulnerability exists in the OTA update task functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to arbitrary file overwrite. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
- Record
GHSA-fmc6-6r82-9j7v- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
A file write vulnerability exists in the OTA update task functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to arbitrary file overwrite. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
- Record
CVE-2021-21968- CVSS 3.1
- 8.3 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H - CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-20
- 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-2021-21968 is a high vulnerability (CVSS 8.1) 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 0.95%, the 61st percentile. No source names a fixed version.