CVE-2023-4569 : Exploit Details and Defense Strategies

This CVE record discusses a memory leak vulnerability found in nft_set_catchall_flush in net/netfilter/nf_tables_api.c in the Linux Kernel. The flaw may permit a local attacker to cause double-deactivations of catchall elements, leading to a memory leak.

Understanding CVE-2023-4569

This section provides an in-depth understanding of the CVE-2023-4569 vulnerability in the Linux Kernel.

What is CVE-2023-4569?

CVE-2023-4569 is a memory leak flaw discovered in nft_set_catchall_flush in net/netfilter/nf_tables_api.c in the Linux Kernel. This vulnerability has the potential to be exploited by a local attacker to trigger double-deactivations of catchall elements, resulting in a memory leak.

The Impact of CVE-2023-4569

The impact of CVE-2023-4569 can allow an attacker to exploit the memory leak vulnerability in the Linux Kernel to potentially cause system instability and resource exhaustion. This could lead to a denial of service (DoS) scenario and compromise the confidentiality of sensitive information.

Technical Details of CVE-2023-4569

This section delves into the technical details associated with CVE-2023-4569.

Vulnerability Description

The vulnerability resides in nft_set_catchall_flush in net/netfilter/nf_tables_api.c in the Linux Kernel, allowing a local attacker to trigger double-deactivations of catchall elements, resulting in a memory leak.

Affected Systems and Versions

Kernel version 6.5-rc7: Unaffected
Red Hat Enterprise Linux 6: Affected
Red Hat Enterprise Linux 7: Unaffected
Red Hat Enterprise Linux 8: Unaffected
Red Hat Enterprise Linux 9: Unaffected
Fedora: Unaffected

Exploitation Mechanism

The vulnerability can be exploited by a local attacker to perform double-deactivations of catchall elements, leading to a memory leak within the Linux Kernel.

Mitigation and Prevention

To mitigate the risks associated with CVE-2023-4569, certain steps can be taken for immediate response and long-term security practices.

Immediate Steps to Take

A mitigation strategy involves skipping the loading of the affected module "nftables" onto the system until a fix is available. Implementing a blacklist mechanism can prevent the driver from loading at boot time. Refer to Blacklisting a Kernel Module for detailed instructions.

Long-Term Security Practices

Implementing robust security measures, such as regular security updates, monitoring, and access control mechanisms, can enhance the overall security posture and resilience of the system against potential vulnerabilities like CVE-2023-4569.

Patching and Updates

Stay informed about security patches released by the Linux Kernel and Red Hat for addressing CVE-2023-4569. Regularly update the affected systems with the latest security patches to mitigate the vulnerability effectively.