GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2021-35951 (GCVE-0-2021-35951)

Vulnerability from cvelistv5 – Published: 2022-12-26 00:00 – Updated: 2025-04-14 18:30
VLAI
Summary
fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows an Unauthenticated Remote attacker to send a malicious firmware update via BLE and brick the device.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-04-14 14:49 UTC
CWE
Assigner
References
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T00:47:42.582Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.fastrack.in/shop/watch-smart-wearables-reflex-2"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://payatu.com/advisory/fastrack-reflex-unauthenticated-firmware-update"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-35951",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-04-14T14:49:17.526849Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "description": "CWE-noinfo Not enough information",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-04-14T18:30:26.765Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows an Unauthenticated Remote attacker to send a malicious firmware update via BLE and brick the device."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2022-12-26T00:00:00.000Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "url": "https://www.fastrack.in/shop/watch-smart-wearables-reflex-2"
        },
        {
          "url": "https://payatu.com/advisory/fastrack-reflex-unauthenticated-firmware-update"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2021-35951",
    "datePublished": "2022-12-26T00:00:00.000Z",
    "dateReserved": "2021-06-29T00:00:00.000Z",
    "dateUpdated": "2025-04-14T18:30:26.765Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-35951",
      "date": "2026-09-17",
      "epss": "0.00891",
      "percentile": "0.57681"
    },
    "fkie_nvd": {
      "configurations": "[{\"operator\": \"AND\", \"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:o:fastrack:reflex_2.0_firmware:90.89:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"EE456490-17F2-47BD-81AD-ECFDC8407571\"}]}, {\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": false, \"criteria\": \"cpe:2.3:h:fastrack:reflex_2.0:-:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"9BE152C4-4620-4FDB-A819-DB77BA3C587E\"}]}]}]",
      "descriptions": "[{\"lang\": \"en\", \"value\": \"fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows an Unauthenticated Remote attacker to send a malicious firmware update via BLE and brick the device.\"}, {\"lang\": \"es\", \"value\": \"fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker permite a un atacante remoto no autenticado enviar una actualizaci\\u00f3n de firmware maliciosa a trav\\u00e9s de BLE y bloquear el dispositivo.\"}]",
      "id": "CVE-2021-35951",
      "lastModified": "2024-11-21T06:12:49.140",
      "metrics": "{\"cvssMetricV31\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"baseScore\": 7.5, \"baseSeverity\": \"HIGH\", \"attackVector\": \"NETWORK\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"NONE\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"NONE\", \"availabilityImpact\": \"HIGH\"}, \"exploitabilityScore\": 3.9, \"impactScore\": 3.6}]}",
      "published": "2022-12-26T06:15:09.770",
      "references": "[{\"url\": \"https://payatu.com/advisory/fastrack-reflex-unauthenticated-firmware-update\", \"source\": \"cve@mitre.org\", \"tags\": [\"Third Party Advisory\"]}, {\"url\": \"https://www.fastrack.in/shop/watch-smart-wearables-reflex-2\", \"source\": \"cve@mitre.org\", \"tags\": [\"Permissions Required\"]}, {\"url\": \"https://payatu.com/advisory/fastrack-reflex-unauthenticated-firmware-update\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Third Party Advisory\"]}, {\"url\": \"https://www.fastrack.in/shop/watch-smart-wearables-reflex-2\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Permissions Required\"]}]",
      "sourceIdentifier": "cve@mitre.org",
      "vulnStatus": "Modified",
      "weaknesses": "[{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"description\": [{\"lang\": \"en\", \"value\": \"NVD-CWE-noinfo\"}]}]"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-35951\",\"sourceIdentifier\":\"cve@mitre.org\",\"published\":\"2022-12-26T06:15:09.770\",\"lastModified\":\"2025-04-14T19:15:29.943\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows an Unauthenticated Remote attacker to send a malicious firmware update via BLE and brick the device.\"},{\"lang\":\"es\",\"value\":\"fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker permite a un atacante remoto no autenticado enviar una actualizaci\u00f3n de firmware maliciosa a trav\u00e9s de BLE y bloquear el dispositivo.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6},{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"NVD-CWE-noinfo\"}]}],\"configurations\":[{\"operator\":\"AND\",\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fastrack:reflex_2.0_firmware:90.89:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"EE456490-17F2-47BD-81AD-ECFDC8407571\"}]},{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":false,\"criteria\":\"cpe:2.3:h:fastrack:reflex_2.0:-:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"9BE152C4-4620-4FDB-A819-DB77BA3C587E\"}]}]}],\"references\":[{\"url\":\"https://payatu.com/advisory/fastrack-reflex-unauthenticated-firmware-update\",\"source\":\"cve@mitre.org\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.fastrack.in/shop/watch-smart-wearables-reflex-2\",\"source\":\"cve@mitre.org\",\"tags\":[\"Permissions Required\"]},{\"url\":\"https://payatu.com/advisory/fastrack-reflex-unauthenticated-firmware-update\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.fastrack.in/shop/watch-smart-wearables-reflex-2\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Permissions Required\"]}]}}",
    "redhat_vex": {
      "current_release_date": "2025-05-29T03:25:07+00:00",
      "cve": "CVE-2021-35951",
      "id": "CVE-2021-35951",
      "initial_release_date": "2021-01-01T00:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "CVE-2021-35951",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-35951.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://www.fastrack.in/shop/watch-smart-wearables-reflex-2\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://payatu.com/advisory/fastrack-reflex-unauthenticated-firmware-update\", \"tags\": [\"x_transferred\"]}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2024-08-04T00:47:42.582Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2021-35951\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2025-04-14T14:49:17.526849Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"description\": \"CWE-noinfo Not enough information\"}]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2025-04-14T14:51:02.809Z\"}}], \"cna\": {\"affected\": [{\"vendor\": \"n/a\", \"product\": \"n/a\", \"versions\": [{\"status\": \"affected\", \"version\": \"n/a\"}]}], \"references\": [{\"url\": \"https://www.fastrack.in/shop/watch-smart-wearables-reflex-2\"}, {\"url\": \"https://payatu.com/advisory/fastrack-reflex-unauthenticated-firmware-update\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows an Unauthenticated Remote attacker to send a malicious firmware update via BLE and brick the device.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"text\", \"description\": \"n/a\"}]}], \"providerMetadata\": {\"orgId\": \"8254265b-2729-46b6-b9e3-3dfca2d5bfca\", \"shortName\": \"mitre\", \"dateUpdated\": \"2022-12-26T00:00:00.000Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2021-35951\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-04-14T18:30:26.765Z\", \"dateReserved\": \"2021-06-29T00:00:00.000Z\", \"assignerOrgId\": \"8254265b-2729-46b6-b9e3-3dfca2d5bfca\", \"datePublished\": \"2022-12-26T00:00:00.000Z\", \"assignerShortName\": \"mitre\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.1"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.