How severe is CVE-2021-42553?

CVE-2021-42553 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-42553 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42553?

CVE-2021-42553 affects St Stm32 Mw Usb Host. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42553?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-42553 published?

CVE-2021-42553 was published on 2022-10-21 and last updated on 2026-06-17.

CVE-2021-42553

CVE-2021-42553 is a medium-severity vulnerability in St Stm32 Mw Usb Host with a CVSS 3.x base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: Medium (CVSS 3.x base score 6.8)
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: St Stm32 Mw Usb Host
Published: 2022-10-21
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-42553?: 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.
How severe is CVE-2021-42553?: CVE-2021-42553 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-42553 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42553?: CVE-2021-42553 affects St Stm32 Mw Usb Host. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42553?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-42553 published?: CVE-2021-42553 was published on 2022-10-21 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:st:stm32_mw_usb_host:-:*:*:*:*:*:*:*

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