CVE-2022-47942 : Vulnerability Insights and Analysis

An issue was discovered in ksmbd in the Linux kernel 5.15 through 5.19 before 5.19.2. The vulnerability involves a heap-based buffer overflow in set_ntacl_dacl, specifically related to the use of SMB2_QUERY_INFO_HE after a malformed SMB2_SET_INFO_HE command.

Understanding CVE-2022-47942

This section provides insights into the nature and impact of the CVE-2022-47942 vulnerability.

What is CVE-2022-47942?

CVE-2022-47942 is a heap-based buffer overflow vulnerability found in the Linux kernel versions 5.15 through 5.19 before 5.19.2. It is related to a specific sequence of SMB2 commands that can lead to exploitation.

The Impact of CVE-2022-47942

The heap-based buffer overflow in set_ntacl_dacl can be exploited by an attacker to potentially execute arbitrary code or crash the system. This vulnerability poses a significant risk to the security and stability of affected systems.

Technical Details of CVE-2022-47942

In this section, we delve into the technical aspects of the CVE-2022-47942 vulnerability.

Vulnerability Description

The vulnerability arises due to improper handling of SMB2 commands in the ksmbd module of the Linux kernel, leading to a heap-based buffer overflow in the set_ntacl_dacl function.

Affected Systems and Versions

All Linux kernel versions between 5.15 and 5.19 (exclusive of 5.19.2) are affected by CVE-2022-47942. It is crucial for users of these versions to take immediate action.

Exploitation Mechanism

By sending a specially crafted SMB2_SET_INFO_HE command followed by an SMB2_QUERY_INFO_HE command, an attacker can trigger the heap-based buffer overflow in the set_ntacl_dacl function, paving the way for exploitation.

Mitigation and Prevention

To mitigate the risks associated with CVE-2022-47942, users and organizations should take the following steps:

Immediate Steps to Take

Update to Linux kernel version 5.19.2 or later to eliminate the vulnerability.
Follow security advisories from Linux kernel maintainers for any additional recommendations.

Long-Term Security Practices

Regularly update the Linux kernel and system components to patch known vulnerabilities.
Implement network security measures to restrict unauthorized access to vulnerable services.

Patching and Updates

Apply patches released by the Linux kernel development team promptly.
Monitor for any future security advisories related to the Linux kernel to stay informed and protected.