CVEs-PoC/2021/CVE-2021-3640.md

CVE-2021-3640

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.

POC

Reference

• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/bluetooth/sco.c?h=v5.16&id=99c23da0eed4fd20cae8243f2b51e10e66aa0951
• https://ubuntu.com/security/CVE-2021-3640
• https://www.openwall.com/lists/oss-security/2021/07/22/1

Github

• https://github.com/ARPSyndicate/cvemon