CVE-2021-3640
A flaw use-after-free in function sco_sock_sendmsg() of the Linux kernel HCI subsystem was found in the way user calls ioct…
- Published
- Updated
- Reserved
- Assigned by
- redhat
Description
A flaw use-after-free in function sco_sock_sendmsg() of the Linux kernel HCI subsystem was found in the way user calls ioct UFFDIO_REGISTER or other way triggers race condition of the call sco_conn_del() together with the call sco_sock_sendmsg() with the expected controllable faulting memory page. A privileged local user could use this flaw to crash the system or escalate their privileges on the system.
Timeline
ID reserved
By redhat
- 8 months later
· 8 months later
Published
- 2 years later
· 2 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 | High7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.37% · top 69% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.0.
Weakness
Affected products
kernel
- affected Affects kernel v5.15.3 and prior, Fixed in v5.16-rc1 and above.
References (9)
- https://bugzilla.redhat.com/show_bug.cgi?id=1980646 (opens in a new tab)x_refsource_MISCx_transferred
- https://ubuntu.com/security/CVE-2021-3640 (opens in a new tab)x_refsource_MISCx_transferred
- https://www.openwall.com/lists/oss-security/2021/07/22/1 (opens in a new tab)x_refsource_MISCx_transferred
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/bluetooth/sco.c?h=v5.16&id=99c23da0eed4fd20cae8243f2b51e10e66aa0951 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/torvalds/linux/commit/99c23da0eed4fd20cae8243f2b51e10e66aa0951 (opens in a new tab)x_refsource_MISCx_transferred
- [debian-lts-announce] 20220309 [SECURITY] [DLA 2940-1] linux security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- [debian-lts-announce] 20220309 [SECURITY] [DLA 2941-1] linux-4.19 security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- DSA-5096 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- https://security.netapp.com/advisory/ntap-20220419-0003/ (opens in a new tab)x_refsource_CONFIRMx_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)
- 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://trackcve.app/cve/CVE-2021-3640)Record last updated .