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CVE-2021-42553

Status: ModifiedCritical (9.8)—

A buffer overflow vulnerability in stm32_mw_usb_host of STMicroelectronics in versions before 3.5.1 allows an attacker to execute arbitrary code when the descriptor contains more endpoints than USBH_MAX_NUM_ENDPOINTS. The library is typically integrated when using a RTOS such as FreeRTOS on STM32 MCUs.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

ST — Stm32 MW USB Host

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2021-42553",
  "cveTags": [],
  "metrics": {
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        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-42553",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2025-05-07T20:06:01.309946Z"
        }
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    "cvssMetricV31": [
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          "integrityImpact": "HIGH",
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          "confidentialityImpact": "HIGH"
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          "product": "STM32 USB Host Library",
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  "published": "2022-10-21T10:15:12.470",
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      "source": "vulnerability@ncsc.ch"
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    {
      "url": "https://github.com/STMicroelectronics/stm32_mw_usb_host/pull/4",
      "tags": [
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      "url": "https://github.com/STMicroelectronics/stm32_mw_usb_host/pull/4",
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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  "vulnStatus": "Modified",
  "weaknesses": [
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      "source": "nvd@nist.gov",
      "description": [
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          "value": "CWE-120"
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  "descriptions": [
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      "lang": "en",
      "value": "A buffer overflow vulnerability in stm32_mw_usb_host of STMicroelectronics in versions before 3.5.1 allows an attacker to execute arbitrary code when the descriptor contains more endpoints than USBH_MAX_NUM_ENDPOINTS. The library is typically integrated when using a RTOS such as FreeRTOS on STM32 MCUs."
    },
    {
      "lang": "es",
      "value": "Una vulnerabilidad de desbordamiento de búfer en la función stm32_mw_usb_host de STMicroelectronics permite a un atacante ejecutar código arbitrario cuando el descriptor contiene más endpoints que USBH_MAX_NUM_ENDPOINTS. La librería es integrada normalmente cuando es usado un RTOS como FreeRTOS en los MCUs STM32"
    }
  ],
  "lastModified": "2026-06-17T04:09:49.007",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
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  "sourceIdentifier": "vulnerability@ncsc.ch"
}