How severe is CVE-2021-35954?

CVE-2021-35954 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2021-35954 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-35954?

CVE-2021-35954 affects Fastrack Reflex 2.0 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-35954?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-35954 published?

CVE-2021-35954 was published on 2022-12-26 and last updated on 2026-06-17.

CVE-2021-35954

CVE-2021-35954 is a high-severity vulnerability in Fastrack Reflex 2.0 Firmware with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 8.1)
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Fastrack Reflex 2.0 Firmware
Published: 2022-12-26
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-35954?: 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.
How severe is CVE-2021-35954?: CVE-2021-35954 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2021-35954 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-35954?: CVE-2021-35954 affects Fastrack Reflex 2.0 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-35954?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-35954 published?: CVE-2021-35954 was published on 2022-12-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:fastrack:reflex_2.0_firmware:90.89:*:*:*:*:*:*:*

More vulnerabilities in Fastrack Reflex 2.0 Firmware

CVE-2021-35953 — High (CVSS 7.5): fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows a Remote attacker to cause a Denial of Service (device…
CVE-2021-35951 — High (CVSS 7.5): fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows an Unauthenticated Remote attacker to send a malicious…
CVE-2021-35952 — Medium (CVSS 5.3): fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows a Remote attacker to change the time, date, and month…

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