CVE-2023-6606 Explained : Impact and Mitigation

An out-of-bounds read vulnerability in smbcalcsize has been discovered in the Linux Kernel, identified as CVE-2023-6606. This vulnerability has a high severity level and could potentially be exploited by a local attacker to crash the system or leak internal kernel information.

Understanding CVE-2023-6606

The vulnerability resides in the smbCalcSize function in fs/smb/client/netmisc.c within the Linux Kernel. It has the potential to impact the security of affected systems, particularly those running Red Hat Enterprise Linux versions 6 to 9 and Fedora.

What is CVE-2023-6606?

The CVE-2023-6606 vulnerability is classified as an out-of-bounds read issue, which falls under CWE-125. This type of vulnerability allows unauthorized access to memory locations beyond the boundaries of an array or buffer, leading to potential system crashes or data leakage.

The Impact of CVE-2023-6606

If exploited, this vulnerability can result in a local attacker causing system instability, crashes, or potentially accessing sensitive kernel information. The confidentiality and availability of the affected systems may be compromised.

Technical Details of CVE-2023-6606

The relevant details regarding CVE-2023-6606 include the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The out-of-bounds read vulnerability in smbCalcSize within the Linux Kernel can be leveraged by a local attacker to disrupt system operations or extract sensitive kernel data.

Affected Systems and Versions

The following systems are affected by CVE-2023-6606:

Red Hat Enterprise Linux 6, 7, 8, 9
Fedora

Exploitation Mechanism

The vulnerability in smbCalcSize can be exploited locally, with low privileges required. An attacker could potentially trigger an out-of-bounds read to compromise the system integrity and confidentiality.

Mitigation and Prevention

To address CVE-2023-6606 and enhance system security, immediate steps, long-term security practices, and patching procedures are recommended.

Immediate Steps to Take

Prevent the loading of the cifs module to mitigate the vulnerability.
Refer to the provided link for instructions on blacklisting kernel modules to prevent automatic loading.

Long-Term Security Practices

Regularly update and patch the systems with the latest security fixes.
Implement access controls and monitoring mechanisms to detect and prevent potential attacks targeting out-of-bounds read vulnerabilities.

Patching and Updates

Apply the necessary security patches provided by Red Hat for affected operating systems to mitigate the CVE-2023-6606 vulnerability effectively. Regularly check for updates and apply them promptly to maintain the security of the systems.