CVE-2021-3323
Integer Underflow in 6LoWPAN IPHC Header Uncompression in Zephyr
Integer Underflow in 6LoWPAN IPHC Header Uncompression in Zephyr. Zephyr versions >= >=2.4.0 contain Integer Underflow (Wrap or Wraparound) (CWE-191). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-89j6-qpxf-pfpc
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Integer Underflow in 6LoWPAN IPHC Header Uncompression in Zephyr
Integer Underflow in 6LoWPAN IPHC Header Uncompression in Zephyr. Zephyr versions >= >=2.4.0 contain Integer Underflow (Wrap or Wraparound) (CWE-191). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-89j6-qpxf-pfpc
- Record
CVE-2021-3323- CVSS 3.1
- 8.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L - Weakness
- CWE-191
- Updated
- 2026-11-02
EUVDEUVD-2021-26654
Integer Underflow in 6LoWPAN IPHC Header Uncompression in Zephyr. Zephyr versions >= >=2.4.0 contain Integer Underflow (Wrap or Wraparound) (CWE-191). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-89j6-qpxf-pfpc
- Record
EUVD-2021-26654- CVSS 3.1
- 8.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L - Updated
- 2026-11-03
NVD
Integer Underflow in 6LoWPAN IPHC Header Uncompression in Zephyr. Zephyr versions >= >=2.4.0 contain Integer Underflow (Wrap or Wraparound) (CWE-191). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-89j6-qpxf-pfpc
- Record
CVE-2021-3323- CVSS 3.1
- 8.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- 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-2021-3323 is a high vulnerability (CVSS 8.3) 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 0.92%, the 60th percentile. No source names a fixed version.