#VU99444 Use-after-free in Linux kernel - CVE-2024-50086

Vulnerability identifier: #VU99444

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2024-50086

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 within the smb2_check_user_session(), smb2_sess_setup() and smb2_session_logoff() functions in fs/smb/server/smb2pdu.c, within the __handle_ksmbd_work() function in fs/smb/server/server.c, within the ksmbd_expire_session(), ksmbd_session_lookup_slowpath(), ksmbd_session_lookup_all() and __session_create() functions in fs/smb/server/mgmt/user_session.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.15 - 5.15.171, 6.1 - 6.1.114, 6.6 - 6.6.58, 6.11 - 6.11.5, 6.12

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External links
https://git.kernel.org/stable/c/a9839c37fd813b432988f58a9d9dd59253d3eb2c
https://git.kernel.org/stable/c/5511999e9615e4318e9142d23b29bd1597befc08
https://git.kernel.org/stable/c/ee371898b53a9b9b51c02d22a8c31bfb86d45f0d
https://git.kernel.org/stable/c/7aa8804c0b67b3cb263a472d17f2cb50d7f1a930
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.171
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.1.114
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.11.5
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.6.58

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Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?