Cyber Resilience

CVE-2021-21964

HighPublic PoC

Published: 04 February 2022

Published
04 February 2022
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.4 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H
EPSS Score 0.0022 44.8th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-21964 is a high-severity Improper Access Control (CWE-284) vulnerability in Sealevel Seaconnect 370W Firmware. Its CVSS base score is 7.4 (High).

Operationally, ranked at the 44.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

sealevel
seaconnect 370w firmware
1.3.34

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-284 CWE-306

Device lock enforces restricted access until re-authentication, directly reducing unauthorized use of active sessions.

addresses: CWE-284 CWE-306

Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.

addresses: CWE-284 CWE-306

Requiring authorization and configuration controls for mobile device connections directly enforces access control and prevents unauthorized devices from reaching organizational systems.

addresses: CWE-284 CWE-306

Provides a tamperproof, always-invoked, and verifiable mechanism to enforce access control policies.

addresses: CWE-284 CWE-306

Provides capability to review session content, directly detecting violations of access control.

addresses: CWE-284 CWE-306

Control assessments verify that access controls are implemented correctly and operating as intended, detecting improper access control before exploitation.

addresses: CWE-284 CWE-306

Certification requires independent assessment confirming access controls are implemented correctly and effective.

addresses: CWE-284 CWE-306

Restricting available functions and services reduces the attack surface and enforces proper access control boundaries.

References