CVE-2020-27484: Garmin Forerunner 235 Firmware

Critical severity, CVSS 9.9. EPSS: 1.8% chance of exploitation in the next 30 days.

Garmin Forerunner 235 before 8.20 is affected by: Integer Overflow. The component is: ConnectIQ TVM. The attack vector is: To exploit the vulnerability, the attacker must upload a malicious ConnectIQ application to the ConnectIQ store. The ConnectIQ program interpreter fails to check for overflow when allocating the array for the NEWA instruction. This a constrained read/write primitive across the entire MAX32630 address space. A successful exploit would allow a ConnectIQ app store application to escape and perform activities outside the restricted application execution environment.

Affected products

• Garmin Forerunner 235 Firmware: from 7.90, before 8.20 (fixed in 8.20)

Published 2020-11-16. Last modified 2026-06-17.