#VU77498 Race condition in Linux kernel - CVE-2023-32254

Vulnerability identifier: #VU77498

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2023-32254

CWE-ID: CWE-362

Exploitation vector: Network

Exploit availability: No

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

Vendor: Linux Foundation

Description

The vulnerability allows a remote attacker to execute arbitrary code on the system.

The vulnerability exists due to a race condition within fs/ksmbd/mgmt/tree_connect.c in ksmbd in Linux kernel when processing SMB2_TREE_DISCONNECT commands. A remote attacker can trigger a use-after-free error using concurrent smb2 tree disconnect requests and execute arbitrary code on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 6.4, 6.4

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External links
https://www.zerodayinitiative.com/advisories/ZDI-23-702/
https://github.com/torvalds/linux/commit/30210947a343b6b3ca13adc9bfc88e1543e16dd5
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=30210947a343b6b3ca13adc9bfc88e1543e16dd5

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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