CVE-2021-32020
CVE-2021-32020 is a critical-severity vulnerability in Amazon Freertos with a CVSS 3.x base score of 9.8. 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-119.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- CVSS v2: 7.5
- EPSS exploit prediction: 1% (70th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-119
- Affected product: Amazon Freertos
- Published:
- Last modified:
Description
The kernel in Amazon Web Services FreeRTOS before 10.4.3 has insufficient bounds checking during management of heap memory.
Frequently asked questions
- What is CVE-2021-32020?
- The kernel in Amazon Web Services FreeRTOS before 10.4.3 has insufficient bounds checking during management of heap memory.
- How severe is CVE-2021-32020?
- CVE-2021-32020 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-32020 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-32020?
- CVE-2021-32020 affects Amazon Freertos. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-32020?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2021-32020 published?
- CVE-2021-32020 was published on 2021-05-03 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:o:amazon:freertos:*:*:*:*:*:*:*:*
More vulnerabilities in Amazon Freertos
- CVE-2021-31572 — Critical (CVSS 9.8): The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in stream_buffer.c for a stream buffer.
- CVE-2021-31571 — Critical (CVSS 9.8): The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in queue.c for queue creation.
- CVE-2026-77234 — High (CVSS 8.8): Improper input validation in FreeRTOS-Kernel before 11.3.1 might allow an unprivileged task on MPU-enabled ports to…
- CVE-2024-28115 — High (CVSS 8.8): FreeRTOS is a real-time operating system for microcontrollers. FreeRTOS Kernel versions through 10.6.1 do not…
- CVE-2018-16601 — High (CVSS 8.1): An issue was discovered in Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with…
- CVE-2018-16526 — High (CVSS 8.1): Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS…
All CVEs affecting Amazon Freertos →
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