CVE-2021-31572

CRITICALNVD 9.89.8—

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.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 43.9%
KEV: Not listed

Published

April 22, 2021

Last Modified

November 21, 2024

Advisory Details (1)

Auto-updated May 26, 2026

Patch available. Sources: github_commit.

github_commit Patch Available

commit d05b9c123f2b (FreeRTOS/FreeRTOS-Kernel)

Patch available: FreeRTOS/FreeRTOS-Kernel V10.4.3 (contains commit d05b9c123f2b)

https://github.com/FreeRTOS/FreeRTOS-Kernel/commit/d05b9c123f2bf9090bce386a244fc934ae44db5b

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-190Integer Overflow or Wraparound

Data Freshness Timeline

(refreshed 12× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-05 06:09 UTCepss_batch
2026-06-05 06:09 UTCepss_batch
2026-06-04 13:10 UTCepss_batch
2026-06-04 13:10 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 17:59 UTCEG score recompute
2026-05-26 17:59 UTCGHSA enrichment
2026-05-26 13:42 UTCepss_batch

Frequently asked(5)

What is CVE-2021-31572?

CVE-2021-31572 is a critical vulnerability published on April 22, 2021. The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in stream_buffer.c for a stream buffer.

When was CVE-2021-31572 disclosed?

CVE-2021-31572 was first published in the National Vulnerability Database on April 22, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-31572 actively exploited?

CVE-2021-31572 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 43.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-31572?

CVE-2021-31572 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2021-31572?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-31572, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-31572

📅 Published

🔄 Last Modified

📋 Advisory Details (1)

commit d05b9c123f2b (FreeRTOS/FreeRTOS-Kernel)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-31572?

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Frequently asked(5)

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