CVE-2021-3625: Buffer overflow in Zephyr USB DFU DNLOAD

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-10-05 · updated 2026-06-17
Weakness: CWE-122

Description

Buffer overflow in Zephyr USB DFU DNLOAD. Zephyr versions >= v2.5.0 contain Heap-based Buffer Overflow (CWE-122). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-c3gr-hgvr-f363

Affected products

zephyrproject zephyr: from 2.5.0 before 2.7.0 — fixed in 2.7.0

How to fix

Upgrade to a fixed version: zephyrproject zephyr 2.7.0. Check the vendor advisory for mitigations.

References

http://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-c3gr-hgvr-f363
http://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-c3gr-hgvr-f363

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