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Fencer Vulns
critical 9.9

CVE-2020-27484 json

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

published 2020-11-16 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-19994

cvss
9.9
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits
0
none known

Summary

Garmin Forerunner 235 before 8.20 is affected by: Integer 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 fails to check for overflow when allocating the array for the NEWA instruction. This 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.

Patch / fix

  • garmin forerunner_235_firmware 8.20

Exploit prediction

1.77% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0004.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-190 Integer Overflow or Wraparound

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.