Use-after-free in Linux kernel - CVE-2021-33034
Published: June 30, 2021
Vulnerability identifier: #VU54454
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-33034
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error in net/bluetooth/hci_event.c when destroying an hci_chan. A local user can escalate privileges on the system.
How to mitigate CVE-2021-33034
Install updates from vendor's website.
Sources
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.4
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5c4c8c9544099bb9043a10a5318130a943e32fc3
- https://syzkaller.appspot.com/bug?id=2e1943a94647f7732dd6fc60368642d6e8dc91b1
- https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-hci_send_acl
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GI7Z7UBWBGD3ABNIL2DC7RQDCGA4UVQW/
- https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html
- https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html