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CVE Record

CVE-2020-27485: Garmin Forerunner 235 before 8.20 is affected by: Array index error.

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.

UnknownCVSS not scoredNot KEV-listedUpdated
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This flaw affects Garmin Forerunner 235 watches running firmware before 8.20. A malicious ConnectIQ store app could break out of the app sandbox and access memory outside its intended area. Business urgency is mainly for organizations relying on these devices or allowing unmanaged ConnectIQ apps; the bundle does not show active exploitation.

Executive priority

Treat this as targeted device-risk cleanup rather than an enterprise-wide emergency. Prioritize organizations with managed Garmin Forerunner 235 fleets, sensitive operational environments, or permissive third-party app installation policies.

Technical view

ConnectIQ TVM mishandles local-variable indexing in LGETV and LPUTV instructions, enabling out-of-bounds read and write beyond the TVM context allocation. The advisory says this can be leveraged into a constrained read/write primitive across the MAX32630 address space, allowing sandbox escape by a ConnectIQ application.

Likely exposure

Exposure appears limited to Garmin Forerunner 235 devices before firmware 8.20, especially where users can install ConnectIQ store applications. The source bundle does not identify other Garmin models or product lines as affected.

Exploitation context

The described attack requires a malicious ConnectIQ application to be uploaded to the ConnectIQ store and installed. The provided sources do not confirm in-the-wild exploitation, KEV listing, public weaponization, or observed campaigns.

Researcher notes

The core evidence is the CVE description and Atredis advisory reference. Severity, CVSS, CWE, and affected CPE data are absent in the bundle. Do not expand scope beyond Garmin Forerunner 235 before 8.20 without additional vendor evidence.

Mitigation direction

  • Update Garmin Forerunner 235 devices to firmware 8.20 or later where available.
  • Check Garmin support guidance for current firmware and update instructions.
  • Restrict installation of untrusted ConnectIQ applications on managed devices.
  • Remove unnecessary or unknown ConnectIQ applications from exposed devices.
  • Document residual risk for devices that cannot be updated.

Validation and detection

  • Inventory Garmin Forerunner 235 devices and record firmware versions.
  • Confirm whether any devices run firmware earlier than 8.20.
  • Review installed ConnectIQ applications for unknown or unnecessary apps.
  • Verify update completion through device settings or management records.
  • Track exceptions for devices that cannot receive firmware 8.20.
Prepared
Confidence
medium
Sources
3

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

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