CVE-2020-27486 Explained : Impact and Mitigation

Garmin Forerunner 235 before 8.20 is affected by a Buffer Overflow vulnerability in the ConnectIQ TVM component. The exploit involves uploading a malicious ConnectIQ application to the ConnectIQ store, allowing unauthorized activities outside the application's execution environment.

Understanding CVE-2020-27486

This CVE involves a critical vulnerability in Garmin Forerunner 235's ConnectIQ TVM component.

What is CVE-2020-27486?

The vulnerability allows attackers to upload a malicious ConnectIQ application to the ConnectIQ store, leading to a buffer overflow that can overwrite heap data and enable unauthorized activities.

The Impact of CVE-2020-27486

Successful exploitation could permit a ConnectIQ app store application to escape its restricted environment and execute malicious actions.

Technical Details of CVE-2020-27486

This section provides in-depth technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises from the ConnectIQ program interpreter trusting the string length in the PRG file, leading to memory allocation and potential heap data overwrites.

Affected Systems and Versions

Affected System: Garmin Forerunner 235
Vulnerable Version: Before 8.20

Exploitation Mechanism

Attacker uploads a malicious ConnectIQ app to the store
String length manipulation in the PRG file
Memory allocation and potential heap data overwrite

Mitigation and Prevention

Protect your system from CVE-2020-27486 with these mitigation strategies.

Immediate Steps to Take

Update Garmin Forerunner 235 to version 8.20 or later
Avoid downloading apps from untrusted sources

Long-Term Security Practices

Regularly update firmware and applications
Implement secure coding practices to prevent buffer overflows

Patching and Updates

Apply security patches promptly
Monitor vendor communications for security updates