CVE-2023-4732 : Vulnerability Insights and Analysis

This CVE record discusses a vulnerability in the Linux Kernel that may lead to a denial of service issue. The bug is related to a race condition within the memory management subsystem, specifically in the pfn_swap_entry_to_page function.

Understanding CVE-2023-4732

This section delves deeper into the nature and impact of CVE-2023-4732.

What is CVE-2023-4732?

The vulnerability identified as CVE-2023-4732 pertains to a flaw found in the pfn_swap_entry_to_page function in the Linux Kernel. It can be exploited by a local user with specific privileges to trigger a denial of service problem, ultimately causing a system crash.

The Impact of CVE-2023-4732

The impact of CVE-2023-4732 is considered moderate, with a CVSS base score of 4.7. Although the confidentiality and integrity of the system are not compromised, the availability of the affected system is significantly impacted. The severity of this vulnerability is classified as "Medium."

Technical Details of CVE-2023-4732

This section focuses on the technical aspects and specifics of CVE-2023-4732.

Vulnerability Description

The vulnerability arises due to a BUG statement referencing pmd_t x in the pfn_swap_entry_to_page function within the Linux Kernel's memory management subsystem, leading to a denial of service issue.

Affected Systems and Versions

Kernel: Version 5.14-rc1 is unaffected.
Red Hat Enterprise Linux 8:
Versions affected: 4.18.0-513.5.1.rt7.307.el8_9
Red Hat Enterprise Linux 8.8 Extended Update Support:
Versions affected: 4.18.0-477.36.1.el8_8
Red Hat Enterprise Linux 6: Unaffected
Red Hat Enterprise Linux 7: Unaffected
Red Hat Enterprise Linux 9: Unaffected
Fedora: Unaffected

Exploitation Mechanism

The vulnerability can be exploited by a local user with specific privileges, utilizing the race condition within the memory management subsystem to trigger the invalid opcode bug and initiate a denial of service attack.

Mitigation and Prevention

In this section, we discuss the measures to mitigate and protect against the CVE-2023-4732 vulnerability.

Immediate Steps to Take

A possible workaround to mitigate the impact of this vulnerability is to disable Transparent Hugepages. This can help reduce the risk of exploitation until a permanent solution is implemented.

Long-Term Security Practices

Implementing security best practices, such as regular system updates, access control policies, and monitoring for unusual system behavior, can enhance overall system security and resilience against potential vulnerabilities.

Patching and Updates

It is crucial for users of affected systems to stay informed about security updates and patches released by the respective vendors. Applying timely updates can address known vulnerabilities and strengthen the overall security posture of the system.