CVE-2020-27485: Garmin Forerunner 235 before 8.20 is affected by: Array index error. The component is: ConnectIQ TVM. The attack vector is: To exploit the vulnerabili...

Description

Garmin Forerunner 235 before 8.20 is affected by: Array index error. 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 the index provided when accessing the local variable in the LGETV and LPUTV instructions. This provides the ability to both read and write memory outside the bounds of the TVM context allocation. It can be leveraged to construct a use-after-free scenario, leading to 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.

Metrics

CVSS 3.1

9.9/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS Probability

1.63%

73.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-129

Affected Software

Vendor	Product	Versions
Garmin	Forerunner 235 Firmware	>= 7.90, < 8.20

References

https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0005.mdExploit, Third Party Advisory
https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0005.mdExploit, Third Party Advisory

Timeline

Published: Nov 16, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-27485?

Garmin Forerunner 235 before 8.20 is affected by: Array index error. 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 the index provided when accessing the local variable in the LGETV and LPUTV instructions. This provides the ability to both read and write memory outside the bounds of the TVM context allocation. It can be leveraged to construct a use-after-free scenario, leading to 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.

How severe is CVE-2020-27485?

CVE-2020-27485 has a CVSS score of 9.9/10 (CRITICAL severity). The EPSS model estimates a 1.63% probability of exploitation in the next 30 days.

How do I fix CVE-2020-27485?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.