Is CVE-2021-21965 actively exploited?

No active exploitation of CVE-2021-21965 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-21965 be exploited remotely?

Yes. CVE-2021-21965 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-21965?

CVE-2021-21965 has a CVSS score of 9.3 (CRITICAL).

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CRITICAL

CVE-2021-21965

CWE-284Published: February 4, 2022· Updated: Jun 17, 2026

9.3

CVSS v3.1

Official Description

A denial of service vulnerability exists in the SeaMax remote configuration functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. Specially-crafted network packets can lead to denial of service. An attacker can send a malicious packet to trigger this vulnerability.

NVD Source

Technical Analysis

CVE-2021-21965 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 9.3.

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.