CVE-2021-3625
CVE-2021-3625 is a critical-severity vulnerability in Zephyrproject Zephyr with a CVSS 3.x base score of 9.6. 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-787.
Key facts
- Severity: Critical (CVSS 3.x base score 9.6)
- CVSS v2: 7.5
- EPSS exploit prediction: 2% (81st percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-787
- Affected product: Zephyrproject Zephyr
- Published:
- Last modified:
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
Frequently asked questions
- What is CVE-2021-3625?
- 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
- How severe is CVE-2021-3625?
- CVE-2021-3625 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability high.
- Is CVE-2021-3625 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-3625?
- CVE-2021-3625 affects Zephyrproject Zephyr. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-3625?
- 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-2021-3625 published?
- CVE-2021-3625 was published on 2021-10-05 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:*
More vulnerabilities in Zephyrproject Zephyr
- CVE-2022-3806 — Critical (CVSS 9.8): Inconsistent handling of error cases in bluetooth hci may lead to a double free condition of a network buffer.
- CVE-2017-14199 — Critical (CVSS 9.8): A buffer overflow has been found in the Zephyr Project's getaddrinfo() implementation in 1.9.0 and 1.10.0.
- CVE-2018-1000800 — Critical (CVSS 9.8): zephyr-rtos version 1.12.0 contains a NULL base pointer reference vulnerability in sys_ring_buf_put(),…
- CVE-2021-3329 — Critical (CVSS 9.6): Lack of proper validation in HCI Host stack initialization can cause a crash of the bluetooth stack
- CVE-2023-0397 — Critical (CVSS 9.6): A malicious / defect bluetooth controller can cause a Denial of Service due to unchecked input in…
- CVE-2021-3966 — Critical (CVSS 9.6): usb device bluetooth class includes a buffer overflow related to implementation of net_buf_add_mem.
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