A denial of service vulnerability exists in the Modbus configuration functionality of Sealevel Systems, Inc.

published 2022-02-04 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-9135

cvss: 8.6; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits: 0; none known

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.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 18 mo ago (2025-04-15)

Exploit prediction

0.71% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2021-1392 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.0	8.6	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
NVD	3.1	7.4	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H
NVD	2.0	7.1	AV:N/AC:M/Au:N/C:N/I:N/A:C

Affected products

n/a Sealevel

Classification

Weakness

CWE-284 Improper Access Control
CWE-306 Missing Authentication for Critical Functionality

References

talosintelligence.com /vulnerability_reports/TALOS-2021-1392
exploit, third-party-advisory

Sources

CVE List CVE-2021-21964
NVD CVE-2021-21964

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Summary