Cyber Resilience

CVE-2021-21969

HighPublic PoC

Published: 04 February 2022

Published
04 February 2022
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0044 63.6th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-21969 is a high-severity Classic Buffer Overflow (CWE-120) vulnerability in Sealevel Seaconnect 370W Firmware. Its CVSS base score is 8.1 (High).

Operationally, ranked in the top 36.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

An out-of-bounds write vulnerability exists in the HandleSeaCloudMessage functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. The HandleIncomingSeaCloudMessage function uses at [4] the json_object_get_string to populate the p_payload global variable. The p_payload is only 0x100 bytes long, and the total…

more

MQTT message could be up to 0x201 bytes. Because the function json_object_get_string will fill str based on the length of the json’s value and not the actual str size, this would result in a possible out-of-bounds write.

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-120

Platform-independent managed code eliminates the need for unchecked native buffer copies that are the root cause of classic buffer overflows.

addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References