CVE-2021-35954

fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows physically proximate attackers to...

8.1 High

fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows physically proximate attackers to dump the firmware, flash custom malicious firmware, and brick the device via the Serial Wire Debug (SWD) feature.

Attack profile

How easy it is to exploit

Attack vector: Adjacent network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: High
Availability: High

Exploit likelihood

0.33%Down 0.6 points since Dec 26, 2022

What each source reports

NVD Score used 8.1

Record: CVE-2021-35954
CVSS 3.1: 8.1 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Updated: 2026-11-02

CVE List 8.1

Record: CVE-2021-35954
CVSS 3.1: 8.1 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Updated: 2026-11-02

EUVDEUVD-2021-22589 8.1

Record: EUVD-2021-22589
CVSS 3.1: 8.1 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-wh39-w6w2-hmvf 8.1

fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows physically proximate attackers to...

Record: GHSA-wh39-w6w2-hmvf
CVSS 3.1: 8.1 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Updated: 2026-11-02

Affected products

fastrack reflex 2.0 firmware

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-35954 is a high vulnerability (CVSS 8.1) in Fastrack Reflex 2.0 Firmware, published December 26, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.33%, the 26th percentile. No source names a fixed version.