HOMEVULNERABILITIESCVE-2020-27483
CRITICAL

CVE-2020-27483

CWE-129Published: November 16, 2020· Updated: Jun 17, 2026

9.9
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2020-27483 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.9.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeChanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected Vendors & Products

garmin2 product(s)
forerunner 235 firmwareforerunner 235
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (2)

Quick Facts

CVE IDCVE-2020-27483
CVSS Score9.9 / 10
SeverityCRITICAL
WeaknessCWE-129
CISA KEVNo
Affected1 vendor(s)
PublishedNov 16, 2020

Related CVEs (CWE-129)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2020-27483 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.