CVE-2021-21969 : Exploit Details and Defense Strategies

An out-of-bounds write vulnerability exists in Sealevel Systems, Inc. SeaConnect 370W v1.3.34 due to the HandleSeaCloudMessage functionality. This vulnerability could result in a possible out-of-bounds write.

Understanding CVE-2021-21969

This CVE involves an out-of-bounds write vulnerability in a specific functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34.

What is CVE-2021-21969?

CVE-2021-21969 is an out-of-bounds write vulnerability found in the HandleSeaCloudMessage functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. The vulnerability occurs when the p_payload global variable is populated using json_object_get_string, potentially leading to an out-of-bounds write.

The Impact of CVE-2021-21969

The impact of this vulnerability is rated as LOW with a CVSS base score of 3.7. It can result in unauthorized modification of memory, potentially leading to unexpected behavior or system crashes.

Technical Details of CVE-2021-21969

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability arises due to the json_object_get_string function filling str based on the length of the json's value, leading to a possible out-of-bounds write.

Affected Systems and Versions

Sealevel Systems, Inc. SeaConnect 370W v1.3.34 is the affected product version by this vulnerability.

Exploitation Mechanism

The exploitation of this vulnerability involves manipulating the MQTT message to exceed the expected payload length, triggering the out-of-bounds write exploit.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-21969, certain measures should be taken.

Immediate Steps to Take

Update the affected Sealevel Systems, Inc. SeaConnect 370W to a patched version.
Monitor network traffic for any suspicious activity.

Long-Term Security Practices

Regularly apply security patches and updates to all systems.
Conduct security audits and penetration testing to identify vulnerabilities.

Patching and Updates

Refer to the vendor's security advisories for patches addressing this vulnerability.