CVE-2020-27484 : Exploit Details and Defense Strategies

Garmin Forerunner 235 before 8.20 is affected by an Integer Overflow vulnerability in the ConnectIQ TVM component. The vulnerability allows an attacker to upload a malicious ConnectIQ application to the ConnectIQ store, leading to potential exploitation.

Understanding CVE-2020-27484

This CVE involves an Integer Overflow vulnerability in Garmin Forerunner 235's ConnectIQ TVM component.

What is CVE-2020-27484?

The vulnerability arises from a failure to check for overflow when allocating an array for the NEWA instruction in the ConnectIQ program interpreter. This oversight enables a constrained read/write primitive across the entire MAX32630 address space, potentially allowing unauthorized activities.

The Impact of CVE-2020-27484

A successful exploit of this vulnerability could permit a ConnectIQ app store application to escape its restricted execution environment and execute activities beyond its intended scope.

Technical Details of CVE-2020-27484

This section provides more technical insights into the CVE.

Vulnerability Description

The vulnerability in Garmin Forerunner 235 before 8.20 is an Integer Overflow issue within the ConnectIQ TVM component.

Affected Systems and Versions

Affected Product: Garmin Forerunner 235
Vulnerable Version: Before 8.20

Exploitation Mechanism

To exploit this vulnerability, an attacker must upload a malicious ConnectIQ application to the ConnectIQ store, leveraging the unchecked overflow during array allocation.

Mitigation and Prevention

Protecting systems from CVE-2020-27484 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Garmin Forerunner 235 to version 8.20 or later to mitigate the vulnerability.
Avoid downloading and installing untrusted ConnectIQ applications.

Long-Term Security Practices

Regularly update firmware and software to patch known vulnerabilities.
Implement security measures to prevent unauthorized application uploads.

Patching and Updates

Ensure timely installation of security patches and updates to address identified vulnerabilities.