Privilege escalation in Linux kernel SMB support

1) Use-after-free

EUVDB-ID: #VU88818

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-52479

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

The vulnerability exists due to a use-after-free error within the smb20_oplock_break_ack() function in fs/ksmbd/smb2pdu.c and fs/smb/server/smb2pdu.c. A local user can trigger a use-after-free error and escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: All versions

External links

http://git.kernel.org/stable/c/694e13732e830cbbfedb562e57f28644927c33fd
http://git.kernel.org/stable/c/8226ffc759ea59f10067b9acdf7f94bae1c69930
http://git.kernel.org/stable/c/d5b0e9d3563e7e314a850e81f42b2ef6f39882f9
http://git.kernel.org/stable/c/c69813471a1ec081a0b9bf0c6bd7e8afd818afce

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.