CVE-2023-1095 : What You Need to Know

This CVE record was published on February 28, 2023, by Red Hat. The vulnerability identified as CVE-2023-1095 pertains to the nf_tables_updtable function in the Linux kernel netfilter subsystem.

Understanding CVE-2023-1095

This section will delve into the details of CVE-2023-1095, including what it is, its impact, technical aspects, and mitigation strategies.

What is CVE-2023-1095?

The vulnerability lies in nf_tables_updtable, where an error in nf_tables_table_enable leads to a NULL pointer dereference due to a transaction object not being placed on a list, causing list_del() to operate on all-zero list heads.

The Impact of CVE-2023-1095

This vulnerability could be exploited by an attacker to trigger a denial of service (DoS) condition in the affected system, potentially leading to system instability or crashes.

Technical Details of CVE-2023-1095

In this section, we will discuss the technical aspects of CVE-2023-1095, including the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability arises from a flaw in the nf_tables_updtable function, causing a NULL pointer dereference when certain conditions are met, leading to a system crash or instability.

Affected Systems and Versions

The Linux kernel netfilter subsystem versions prior to the fix in version 6.0-rc1 are impacted by CVE-2023-1095. Specifically, the vulnerability affects systems where the nf_tables_updtable function is utilized.

Exploitation Mechanism

An attacker could exploit this vulnerability by sending specially crafted packets to the system, triggering the error in nf_tables_table_enable and subsequently causing the NULL pointer dereference.

Mitigation and Prevention

As CVE-2023-1095 poses a security risk to systems utilizing the vulnerable nf_tables_updtable function, it is crucial to take immediate steps to mitigate the impact and prevent potential exploitation.

Immediate Steps to Take

Organizations should apply the patch provided by the Linux kernel maintainers to fix the vulnerability in version 6.0-rc1.
Network administrators should monitor the system for any unusual behavior or crashes that may indicate a possible exploitation attempt.

Long-Term Security Practices

Implementing proper access controls, network segmentation, and regular security audits can help enhance overall system security and mitigate the risk of similar vulnerabilities in the future.

Patching and Updates

Regularly updating the Linux kernel and associated components is essential to ensure that systems are equipped with the latest security patches and fixes, reducing the risk of known vulnerabilities being exploited.