CVE-2021-21967
An out-of-bounds write vulnerability exists in the OTA update task functionality of Sealevel...
An out-of-bounds 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 denial of service. 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
- None
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
An out-of-bounds 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 denial of service. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
- Record
CVE-2021-21967- CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
EUVDEUVD-2021-9138
An out-of-bounds 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 denial of service. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
- Record
EUVD-2021-9138- CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-8hfr-mj47-7cxj
An out-of-bounds write vulnerability exists in the OTA update task functionality of Sealevel...
An out-of-bounds 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 denial of service. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
- Record
GHSA-8hfr-mj47-7cxj- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
NVD
An out-of-bounds 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 denial of service. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
- Record
CVE-2021-21967- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H - CVSS 2.0
- 7.1 High
AV:N/AC:M/Au:N/C:N/I:N/A:C - Weakness
- CWE-120
- 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-2021-21967 is a medium vulnerability (CVSS 6.5) in Sealevel Systems, Inc. Seaconnect 370w, published April 14, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.74%, the 55th percentile. No source names a fixed version.