LiveActive security incident?Get immediate response
CVE Record

CVE-2020-27486: Garmin Forerunner 235 before 8.20 is affected by: Buffer Overflow.

Garmin Forerunner 235 before 8.20 is affected by: Buffer 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 trusts the string length provided in the data section of the PRG file. It allocates memory for the string immediately, and then copies the string into the TVM object by using a function similar to strcpy. This copy can exceed the length of the allocated string data and overwrite heap data. 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 analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2020-27486 affects Garmin Forerunner 235 watches running firmware before 8.20. A malicious ConnectIQ app could abuse a memory-handling flaw to escape the normal app sandbox. This is mainly a managed-device and wearable policy concern, not a typical server or cloud exposure.

Executive priority

Treat this as a targeted wearable-device risk. It does not indicate broad infrastructure compromise, but organizations managing Garmin watches should confirm firmware status and restrict untrusted ConnectIQ apps.

Technical view

The ConnectIQ TVM interpreter trusts a string length from the PRG data section, allocates memory from that value, then copies string data in a strcpy-like operation. The copy can exceed the allocation, corrupt heap data, and potentially let a ConnectIQ app perform actions outside its restricted runtime.

Likely exposure

Exposure is likely limited to Garmin Forerunner 235 devices running firmware before 8.20 and installing ConnectIQ applications. The provided CVE metadata lists generic affected fields as unavailable, so asset confirmation should rely on device firmware inventory.

Exploitation context

The cited CVE description says exploitation requires uploading a malicious ConnectIQ application to the ConnectIQ store. CISA KEV status is false in the bundle, and no provided source claims active exploitation.

Researcher notes

The key issue is a heap overflow in ConnectIQ TVM PRG string handling. The source bundle does not provide CVSS, CWE, full affected CPEs, proof of exploitation, or detailed vendor remediation beyond the before-8.20 affected version boundary.

Mitigation direction

  • Confirm Garmin Forerunner 235 devices are not running firmware before 8.20.
  • Review Garmin or advisory guidance for supported firmware update paths.
  • Restrict installation of untrusted ConnectIQ apps on managed devices.
  • Remove unnecessary ConnectIQ applications from affected devices.

Validation and detection

  • Inventory Garmin Forerunner 235 devices and record firmware versions.
  • Check whether any devices run firmware earlier than 8.20.
  • Review managed-device policy for ConnectIQ app installation controls.
  • Document whether affected watches are business-managed or personally owned.
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

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2020-27486 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
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

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.