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CVE-2021-3564A flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious…
- 5.5MediumCVSS base score
- 0.48%Exploitation in 30 daysEPSS · top 58% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious HCI TTY Bluetooth device. A local user could use this flaw to crash the system. This flaw affects all the Linux kernel versions starting from 3.13.
Timeline
ID reserved
By redhat
- 15 days later
· 15 days later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.48% · top 58% of all CVEs (14 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
kernel
- affected All Linux kernel versions starting from 3.13
References
References6
- [oss-security] 20210525 CVE-2021-3564 Linux Bluetooth device initialization implementation bug (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- [oss-security] 20210601 Re: CVE-2021-3564 Linux Bluetooth device initialization implementation bug (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- https://bugzilla.redhat.com/show_bug.cgi?id=1964139 (opens in a new tab)x_refsource_MISCx_transferred
- https://www.openwall.com/lists/oss-security/2021/05/25/1 (opens in a new tab)x_refsource_MISCx_transferred
- [debian-lts-announce] 20210623 [SECURITY] [DLA 2689-1] linux security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- [debian-lts-announce] 20210623 [SECURITY] [DLA 2690-1] linux-4.19 security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-26874 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-3564)Record last updated .