CVE-2021-3321
Integer Underflow in Zephyr in IEEE 802154 Fragment Reassembly Header Removal
Integer Underflow in Zephyr in IEEE 802154 Fragment Reassembly Header Removal. Zephyr versions >= >=2.4.0 contain Integer Overflow to Buffer Overflow (CWE-680). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-w44j-66g7-xw99
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Integer Underflow in Zephyr in IEEE 802154 Fragment Reassembly Header Removal
Integer Underflow in Zephyr in IEEE 802154 Fragment Reassembly Header Removal. Zephyr versions >= >=2.4.0 contain Integer Overflow to Buffer Overflow (CWE-680). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-w44j-66g7-xw99
- Record
CVE-2021-3321- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:H - Weakness
- CWE-680
- Updated
- 2026-11-02
EUVDEUVD-2021-26652
Integer Underflow in Zephyr in IEEE 802154 Fragment Reassembly Header Removal. Zephyr versions >= >=2.4.0 contain Integer Overflow to Buffer Overflow (CWE-680). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-w44j-66g7-xw99
- Record
EUVD-2021-26652- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:H - Updated
- 2026-11-03
NVD
Integer Underflow in Zephyr in IEEE 802154 Fragment Reassembly Header Removal. Zephyr versions >= >=2.4.0 contain Integer Overflow to Buffer Overflow (CWE-680). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-w44j-66g7-xw99
- Record
CVE-2021-3321- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:H - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 5.8 Medium
AV:A/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-680, CWE-191
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-3321 is a high vulnerability (CVSS 7.5) in Zephyrproject Zephyr, published October 12, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.76%, the 55th percentile. No source names a fixed version.