CVE-2021-27427

HIGHNVD 7.39.8▲

7.3

RIOT OS version 2020.01.1 is vulnerable to integer wrap-around in its implementation of calloc function, which can lead to arbitrary memory allocation, resulting in unexpected behavior such as a crash or a remote code injection/execution.

CVSS v3: 7.3
EG Score: 9.8(medium)
EPSS: 84.4%
KEV: Not listed

Published

May 3, 2022

Last Modified

November 21, 2024

References (4)

ics-cert@hqhttps://github.com/RIOT-OS/RIOT
ics-cert@hqhttps://www.cisa.gov/uscert/ics/advisories/icsa-21-119-04
af854a3a-2127-422b-91ae-364da2661108https://github.com/RIOT-OS/RIOT
af854a3a-2127-422b-91ae-364da2661108https://www.cisa.gov/uscert/ics/advisories/icsa-21-119-04

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
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2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2021-27427?

CVE-2021-27427 is a high vulnerability published on May 3, 2022. RIOT OS version 2020.01.1 is vulnerable to integer wrap-around in its implementation of calloc function, which can lead to arbitrary memory allocation, resulting in unexpected behavior such as a crash or a remote code injection/execution.

When was CVE-2021-27427 disclosed?

CVE-2021-27427 was first published in the National Vulnerability Database on May 3, 2022, 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-2021-27427 actively exploited?

CVE-2021-27427 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 84.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-27427?

CVE-2021-27427 has a CVSS v3 base score of 7.3 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.8.

How do I remediate CVE-2021-27427?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-27427, 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-2021-27427

📅 Published

🔄 Last Modified

🔗 References (4)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-27427?

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Published

Last Modified

References (4)

Frequently asked(5)

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