How severe is CVE-2020-27484?

CVE-2020-27484 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-2020-27484 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27484?

CVE-2020-27484 affects Garmin Forerunner 235 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-27484?

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-2020-27484 published?

CVE-2020-27484 was published on 2020-11-16 and last updated on 2026-06-17.

CVE-2020-27484

CVE-2020-27484 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-190.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
CVSS v2: 6.5
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
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: 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.

Frequently asked questions

What is CVE-2020-27484?: 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.
How severe is CVE-2020-27484?: CVE-2020-27484 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-2020-27484 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27484?: CVE-2020-27484 affects Garmin Forerunner 235 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-27484?: 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-2020-27484 published?: CVE-2020-27484 was published on 2020-11-16 and last updated on 2026-06-17.

References

https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0004.md

Affected products (1)

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

More vulnerabilities in Garmin Forerunner 235 Firmware

CVE-2020-27486 — Critical (CVSS 9.9): Garmin Forerunner 235 before 8.20 is affected by: Buffer Overflow. The component is: ConnectIQ TVM. The attack vector…
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