### [CVE-2021-21969](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21969)
![](https://img.shields.io/static/v1?label=Product&message=Sealevel%22&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=Sealevel%20Systems%2C%20Inc.%20SeaConnect%20370W%20v1.3.34%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-120%3A%20Buffer%20Copy%20without%20Checking%20Size%20of%20Input%20('Classic%20Buffer%20Overflow')&color=brightgreen)

### Description

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 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.

### POC

#### Reference
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1396

#### Github
No PoCs found on GitHub currently.