Garmin Forerunner 235 before 8.20 is affected by: Buffer Overflow.

published 2020-11-16 5y ago modified 2026-06-17 4mo ago also EUVD-2020-19996

cvss: 9.9; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.9%; EPSS 1.9% chance of exploitation in 30 days, percentile 80%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

garmin forerunner_235_firmware 8.20

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Exploit prediction

1.94% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

github.com https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0006.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	9.9	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P

Classification

Weakness

CWE-120 Buffer Copy without Checking Size of Input

References

github.com /atredispartners/advisories/blob/master/ATREDIS-2020-0006.md
exploit, third-party-advisory

Sources

CVE List CVE-2020-27486
NVD CVE-2020-27486

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