CVE-2023-4207 : Vulnerability Insights and Analysis

This CVE record, assigned by Google, pertains to a use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component, potentially leading to local privilege escalation. The vulnerability was published on September 6, 2023.

Understanding CVE-2023-4207

The vulnerability identified as CVE-2023-4207 involves a specific issue in the Linux kernel's net/sched: cls_fw component that can be exploited to achieve local privilege escalation.

What is CVE-2023-4207?

The CVE-2023-4207 vulnerability in the Linux kernel's net/sched: cls_fw component arises due to a use-after-free scenario, triggered when updating a filter bound to a class. This can result in the referenced class being deleted, leading to a use-after-free condition that can be exploited by an attacker.

The Impact of CVE-2023-4207

The impact of CVE-2023-4207 is classified as a privilege escalation vulnerability (CAPEC-233), potentially allowing an attacker to elevate their privileges on a local system, posing a significant risk to the affected systems.

Technical Details of CVE-2023-4207

The technical details of CVE-2023-4207 provide insight into the vulnerability's description, affected systems, and the exploitation mechanism.

Vulnerability Description

The vulnerability arises from how the fw_change() function in the Linux kernel's net/sched: cls_fw component handles copying the tcf_result struct into a new filter instance, ultimately leading to a use-after-free condition when updating a filter bound to a class.

Affected Systems and Versions

The affected system identified in this CVE is the Linux Kernel, specifically version 3.18 with a version less than 6.5. Systems running these versions are vulnerable to the use-after-free exploit.

Exploitation Mechanism

Exploiting CVE-2023-4207 involves manipulating the tcf_result struct during the update of a filter bound to a class, causing the referenced class to be deleted and opening the door for privilege escalation through the use-after-free scenario.

Mitigation and Prevention

Mitigating and preventing the exploitation of CVE-2023-4207 requires immediate action and long-term security measures to safeguard systems from such vulnerabilities.

Immediate Steps to Take

To address CVE-2023-4207, it is crucial to upgrade past the commit identified as 76e42ae831991c828cffa8c37736ebfb831ad5ec. Implementing this update will mitigate the risk of exploitation associated with this vulnerability.

Long-Term Security Practices

Implementing robust security practices, such as regularly updating systems and maintaining awareness of known vulnerabilities within the Linux Kernel, can help bolster overall system security and reduce the likelihood of successful attacks leveraging CVE-2023-4207.

Patching and Updates

Staying informed about security patches released by the Linux Kernel development team, as well as promptly applying these patches to vulnerable systems, is essential in ensuring ongoing protection against potential exploits like CVE-2023-4207.