{"id":"CVE-2021-42553","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-42553","generatedAt":"2026-10-27T20:53:34.312Z","title":"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.","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.","published":"2022-10-21T10:15:12.000Z","lastModified":"2026-10-08T18:23:29.000Z","status":"Analyzed","sourceIdentifier":"vulnerability@ncsc.ch","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-120"],"affected":["st/stm32 mw usb host"],"epss":{"score":0.01274,"percentile":0.69697,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/STMicroelectronics/stm32_mw_usb_host","tags":["Product"],"source":"vulnerability@ncsc.ch"},{"url":"https://github.com/STMicroelectronics/stm32_mw_usb_host/pull/4","tags":["Patch","Third Party Advisory"],"source":"vulnerability@ncsc.ch"},{"url":"https://github.com/STMicroelectronics/stm32_mw_usb_host","tags":["Product"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/STMicroelectronics/stm32_mw_usb_host/pull/4","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-42553","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}