CVE-2021-21964 Denial of service in Sealevel

High 8.6 Published 4 Feb 2022 Updated 15 Apr 2025

An attacker can cause a denial of service in Sealevel SeaConnect 370W by sending specially crafted network packets to the Modbus configuration interface.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-21964?

CVE-2021-21964 is a high-severity denial of service vulnerability in Sealevel, published on 4 Feb 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A denial of service vulnerability exists in the Modbus 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.

Weakness: CWE-306, CWE-284

Which versions are affected by CVE-2021-21964?

It affects 1 product.

Products include Sealevel Seaconnect 370w Firmware.

How do I fix CVE-2021-21964?

No fix has been published for CVE-2021-21964 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-21964 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21964 exists.

Sources

Also known as GHSA-p3rx-9gw8-x632.