Linux Kernel ksmbd Session Race Condition Remote Code Execution Vulnerability

2023-05-1700:00:00

Quentin Minster (@thalium_team)

www.zerodayinitiative.com

remote code execution

linux kernel

vulnerability

smb2_session_setup

smb2_logoff

lack of proper locking

8.1 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

5.1 Medium

CVSS2

Access Vector

NETWORK

Access Complexity

HIGH

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:N/AC:H/Au:N/C:P/I:P/A:P

0.004 Low

EPSS

Percentile

72.7%

JSON

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Linux Kernel. Authentication is not required to exploit this vulnerability, but only systems with ksmbd enabled are vulnerable. The specific flaw exists within the processing of SMB2_SESSION_SETUP and SMB2_LOGOFF commands. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to execute code in the context of the kernel.