CVE-2021-3455
CVSS v3
7.5
HIGH
EPSS Score
1.1 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
Disconnecting L2CAP channel right after invalid ATT request leads freeze. Zephyr versions >= 2.4.0, >= 2.5.0 contain Use After Free (CWE-416). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-7g38-3x9v-v7vp
Technical details
- Published
- 2021-10-19
Frequently asked questions
What is CVE-2021-3455?
Disconnecting L2CAP channel right after invalid ATT request leads freeze. Zephyr versions >= 2.4.0, >= 2.5.0 contain Use After Free (CWE-416). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-7g38-3x9v-v7vp
Is CVE-2021-3455 actively exploited?
Active exploitation of CVE-2021-3455 has not been confirmed. Its EPSS score was 1.1% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-3455?
CVE-2021-3455 has a CVSS v3 base score of 7.5 (HIGH severity).
Is CVE-2021-3455 affecting your environment?
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