CVE-2021-3323

highpriority · track · 39EPSS 0.009 · 60 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.92% (60th) EPSS

CVSS 7.5 · high

Is it mine?

2 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

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

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.18.3highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:Lsecondary · ENISA EU

v3.18.3highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:Lsecondary · vulnerabilities@zephyrproject.orgexploitability 3.9 · impact 3.7

v3.19criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-191USprimary

affected products (2)

Products and version ranges known to be affected.

zephyrproject-rtos Zephyr2.4.0 → unspecifiedenisa_euvdEU
zephyrproject zephyr2.4.0 → 2.5.0nvdUScpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:*

also known as (2)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-10-12modified 2026-06-17

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+715 more

references (4)

External citations — patches, advisories, analysis.

scry

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