Buffer overflow in Garmin Forerunner 235

CVE-2020-27486

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.

Vulnerability class: Buffer Overflow

EPSS: 0.019 (77.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-27486?
CVE-2020-27486 is a critical-severity vulnerability in Garmin Forerunner 235, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.9/10. Published 2020-11-16.
How severe is CVE-2020-27486?
Critical severity. CVSS v3 base score is 9.9 out of 10.