CVE-2021-3321 json
Integer Underflow in Zephyr in IEEE 802154 Fragment Reassembly Header Removal
published 2021-10-12 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26652
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 55%
- public exploits
- 0
- none known
Summary
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
Patch / fix
- zephyrproject zephyr 2.5.0
Exploit prediction
0.76% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com http://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-w44j-66g7-xw99 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:H |
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 5.8 | AV:A/AC:L/Au:N/C:P/I:P/A:P |
Affected products
- zephyrproject-rtos zephyr
Classification
References
-
github.com
/zephyrproject-rtos/zephyr/security/advisories/GHSA-w44j-66g7-xw99
exploit, patch, third-party-advisory
Sources
- CVE List CVE-2021-3321
- NVD CVE-2021-3321
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