Is CVE-2021-21968 actively exploited?

No active exploitation of CVE-2021-21968 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-21968 be exploited remotely?

Yes. CVE-2021-21968 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-21968?

CVE-2021-21968 has a CVSS score of 8.3 (HIGH).

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HIGH

CVE-2021-21968

CWE-20Published: February 4, 2022· Updated: Jun 17, 2026

8.3

CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2021-21968 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.3.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.