Memory corruption via oversized MQTT name value
Published Feb 4, 2022 · Updated Apr 15, 2025
Out-of-bounds write in SeaConnect 370W 1.3.34 allows man-in-the-middle attackers to corrupt memory via a crafted MQTT message. HandleIncomingSeaCloudMessage passes the JSON name value to json_object_get_string, which copies by token length into the 0x80-byte p_name buffer without checking its capacity. Exploitation requires a man-in-the-middle position on the MQTT path, and the disclosed result is an out-of-bounds memory write rather than demonstrated code execution.
Summary
What happened
Out-of-bounds write in SeaConnect 370W 1.3.34 allows man-in-the-middle attackers to corrupt memory via a crafted MQTT message. HandleIncomingSeaCloudMessage passes the JSON name value to json_object_get_string, which copies by token length into the 0x80-byte p_name buffer without checking its capacity. Exploitation requires a man-in-the-middle position on the MQTT path, and the disclosed result is an out-of-bounds memory write rather than demonstrated code execution.
The record
- CVE
- CVE-2021-21970
- Published
- Feb 4, 2022
- Updated
- Apr 15, 2025
- Vendor
- Sealevel Systems, Inc.
- Product
- SeaConnect 370W
- Classifications
- CWE-787, CWE-120, T0830
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 4, 2022CVE publishedPublication date reported by the CVE source.
- Apr 15, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=Sealevel Systems, Inc. SeaConnect 370W v1.3.34
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- Cisco Talos MQTT payload demonstrationproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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