How severe is CVE-2020-27483?

CVE-2020-27483 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-27483 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27483?

CVE-2020-27483 affects Garmin Forerunner 235 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-27483?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-27483 published?

CVE-2020-27483 was published on 2020-11-16 and last updated on 2026-06-17.

CVE-2020-27483

CVE-2020-27483 is a critical-severity vulnerability in Garmin Forerunner 235 Firmware with a CVSS 3.x base score of 9.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-129.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
CVSS v2: 6.5
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-129
Affected product: Garmin Forerunner 235 Firmware
Published: 2020-11-16
Last modified: 2026-06-17

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.

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 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-27483 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27483?: CVE-2020-27483 affects Garmin Forerunner 235 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-27483?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-27483 published?: CVE-2020-27483 was published on 2020-11-16 and last updated on 2026-06-17.

References

https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0007.md

Affected products (1)

cpe:2.3:o:garmin:forerunner_235_firmware:*:*:*:*:*:*:*:*

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