9.8

CVE-2021-42553: st stm32_mw_usb_host Classic Buffer Overflow

CVSS: 9.8v3.1CriticalAnalyzed
AliasesUBUNTU-CVE-2021-42553
Published 21-10-2022Last modified 07-05-2025
Open JSON

Vulnerability summary

CVE-2021-42553 is a critical (CVSS 9.8) Classic Buffer Overflow vulnerability in st stm32_mw_usb_host. EPSS estimates a 1.27% chance of exploitation in the next 30 days, higher than 69.4% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
1.27%
0%100%
Low · +0.22 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
USN-7472-1

Timeline

  1. 21-10-2022
    PublishedVulnerability first disclosed.
  2. 07-05-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

1.27%

Chance of exploitation in the next 30 days

Percentile

69%

Versus all other CVEs

30-day change

+0.22 pp

From 1.05% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.27%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

St1 product
Stmicroelectronics stm32cube1 product
Ubuntu1 product
  • micropython< 1.12-1ubuntu0.1~esm1 | < 1.17+ds-1.1ubuntu2+esm1 | < 1.22.1+ds-1ubuntu0.24.04.1~esm1 | All versions (No fix recorded)

3 vendors · 3 products

References

5 links