CVE-2020-27483: 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 trusts the offset provided for the stack value duplication instruction, DUP. The offset is unchecked and memory prior to the start of the execution stack can be read and treated as a TVM object. A successful exploit could use the vulnerability to leak runtime information such as the heap handle or pointer for a number of TVM context variables. Some reachable values may be controlled enough to forge a TVM object on the stack, leading to possible remote code execution.

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

2.06%

78.9th 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-2020-0007.mdExploit, Third Party Advisory
https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0007.mdExploit, Third Party Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2020-27483?

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 trusts the offset provided for the stack value duplication instruction, DUP. The offset is unchecked and memory prior to the start of the execution stack can be read and treated as a TVM object. A successful exploit could use the vulnerability to leak runtime information such as the heap handle or pointer for a number of TVM context variables. Some reachable values may be controlled enough to forge a TVM object on the stack, leading to possible remote code execution.

How severe is CVE-2020-27483?

CVE-2020-27483 has a CVSS score of 9.9/10 (CRITICAL severity). The EPSS model estimates a 2.06% probability of exploitation in the next 30 days.

How do I fix CVE-2020-27483?

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.