Fix for Slub Overflow in ksmbd_decode_ntlmssp_auth_blob() to Prevent Key Exchange Code Overflow

CVE-2023-52440

What is CVE-2023-52440?

CVE-2023-52440 is a critical vulnerability identified within the Linux kernel's handling of SMB (Server Message Block) communication, specifically related to the ksmbd_decode_ntlmssp_auth_blob() function. This function is responsible for processing NTLMSSP authentication blobs for Windows interoperation. The vulnerability arises from a potential stack-based buffer overflow, which occurs when the SessionKey.Length field exceeds the size of the allocated session key array. This overflow creates a potential vector for attackers to manipulate memory, leading to undefined behavior or system crashes.

Given the prevalence of SMB in enterprise environments for file sharing and network resource access, a successful exploit of this vulnerability could have severe ramifications. Attackers could leverage this flaw to execute arbitrary code in the kernel space, potentially gaining elevated privileges and accessing sensitive data, modifying system configurations, or disrupting service availability.

Potential impact of CVE-2023-52440

1. Remote Code Execution: Exploiters could potentially execute arbitrary code with kernel-level privileges, allowing them to control affected systems completely and deploy malware or backdoors undetected.

2. Data Compromise: The exploitation of this vulnerability could lead to unauthorized access to confidential files and sensitive information, risking data breaches that could impact the integrity and confidentiality of organizational data.

3. Denial of Service: The vulnerability may be exploited to perform denial-of-service attacks, leading to system crashes or instability. This could disrupt business operations and lead to significant downtime, affecting productivity and service availability for users.

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