How severe is CVE-2021-21967?

CVE-2021-21967 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-21967 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21967?

CVE-2021-21967 affects Sealevel Seaconnect 370w Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21967?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-21967 published?

CVE-2021-21967 was published on 2022-04-14 and last updated on 2026-06-17.

CVE-2021-21967

CVE-2021-21967 is a medium-severity vulnerability in Sealevel Seaconnect 370w Firmware with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 7.1
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Sealevel Seaconnect 370w Firmware
Published: 2022-04-14
Last modified: 2026-06-17

Description

An out-of-bounds write vulnerability exists in the OTA update task functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to denial of service. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.

Frequently asked questions

What is CVE-2021-21967?: An out-of-bounds write vulnerability exists in the OTA update task functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to denial of service. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
How severe is CVE-2021-21967?: CVE-2021-21967 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-21967 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21967?: CVE-2021-21967 affects Sealevel Seaconnect 370w Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21967?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-21967 published?: CVE-2021-21967 was published on 2022-04-14 and last updated on 2026-06-17.

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1394

Affected products (1)

cpe:2.3:o:sealevel:seaconnect_370w_firmware:1.3.34:*:*:*:*:*:*:*

More vulnerabilities in Sealevel Seaconnect 370w Firmware

CVE-2021-21961 — Critical (CVSS 10.0): A stack-based buffer overflow vulnerability exists in the NBNS functionality of Sealevel Systems, Inc. SeaConnect 370W…
CVE-2021-21960 — Critical (CVSS 10.0): A stack-based buffer overflow vulnerability exists in both the LLMNR functionality of Sealevel Systems, Inc. SeaConnect…
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