Vulnerability identifier: #VU63769

Vulnerability risk: Low

CVSSv3.1: 5.8 [CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3640

CWE-ID: CWE-416

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error in sco_sock_sendmsg() function of the Linux kernel HCI subsystem. A privileged local user can call ioct UFFDIO_REGISTER or other way trigger race condition to escalate privileges on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel:

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External links
http://github.com/torvalds/linux/commit/99c23da0eed4fd20cae8243f2b51e10e66aa0951
http://bugzilla.redhat.com/show_bug.cgi?id=1980646
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/bluetooth/sco.c?h=v5.16&id=99c23da0eed4fd20cae8243f2b51e10e66aa0951
http://www.openwall.com/lists/oss-security/2021/07/22/1
http://ubuntu.com/security/CVE-2021-3640
http://lists.debian.org/debian-lts-announce/2022/03/msg00012.html
http://lists.debian.org/debian-lts-announce/2022/03/msg00011.html
http://www.debian.org/security/2022/dsa-5096
http://security.netapp.com/advisory/ntap-20220419-0003/

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.