What’s Vulnerable › Vulnerabilities

CVE-2021-22547: Buffer overrun in Google Cloud IoT Device SDK for Embedded C

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-05-04 · updated 2026-06-17
• Weakness: CWE-120

Description

In IoT Devices SDK, there is an implementation of calloc() that doesn't have a length check. An attacker could pass in memory objects larger than the buffer and wrap around to have a smaller buffer than required, allowing the attacker access to the other parts of the heap. We recommend upgrading the Google Cloud IoT Device SDK for Embedded C used to 1.0.3 or greater.

Affected products

• Google LLC Google Cloud IoT Device SDK for Embedded C: before 1.0.3 — fixed in 1.0.3

How to fix

Upgrade to a fixed version: Google LLC Google Cloud IoT Device SDK for Embedded C 1.0.3. Check the vendor advisory for mitigations.

References

• https://github.com/GoogleCloudPlatform/iot-device-sdk-embedded-c/blob/master/RELEASE-NOTES.md
• https://github.com/GoogleCloudPlatform/iot-device-sdk-embedded-c/pull/119
• https://github.com/GoogleCloudPlatform/iot-device-sdk-embedded-c/blob/master/RELEASE-NOTES.md
• https://github.com/GoogleCloudPlatform/iot-device-sdk-embedded-c/pull/119

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