CVE-2023-3107 : Vulnerability Insights and Analysis

This CVE-2023-3107, assigned by FreeBSD, was published on August 1, 2023, and affects FreeBSD systems. It involves a remote denial of service vulnerability in IPv6 fragment reassembly.

Understanding CVE-2023-3107

CVE-2023-3107 is a security flaw that can be exploited through carefully crafted IPv6 packets, causing an integer overflow in the calculation of a fragment reassembled packet's payload length field. This can lead to a kernel panic and result in a denial of service for the affected system.

What is CVE-2023-3107?

The vulnerability in CVE-2023-3107 allows an attacker to trigger a kernel panic by exploiting the integer overflow in the calculation of IPv6 fragment reassembled packet's payload length field. This type of attack falls under CAPEC-128 - Integer Attacks.

The Impact of CVE-2023-3107

The impact of CVE-2023-3107 is significant as it can lead to a denial of service by causing a kernel panic on affected FreeBSD systems. This type of attack targets the integer handling in the system.

Technical Details of CVE-2023-3107

The vulnerability description involves triggering an integer overflow in the calculation of a fragment reassembled packet's payload length field. The affected systems include FreeBSD versions less than 13.2-RELEASE-p2, less than 13.1-RELEASE-p9, and less than 12.4-RELEASE-p4.

Vulnerability Description

A carefully crafted set of IPv6 packets can exploit an integer overflow in the calculation of IPv6 fragment reassembled packet's payload length field, leading to a denial of service through a kernel panic.

Affected Systems and Versions

FreeBSD versions 13.2-RELEASE, 13.1-RELEASE, and 12.4-RELEASE are affected by this vulnerability if they are not patched with the respective updates.

Exploitation Mechanism

The vulnerability can be exploited by sending specially crafted IPv6 packets to trigger the integer overflow, impacting the calculation of the fragment reassembled packet's payload length field.

Mitigation and Prevention

To mitigate the risks associated with CVE-2023-3107, immediate actions can be taken to prevent further exploitation and ensure the security of FreeBSD systems.

Immediate Steps to Take

Users can disable IPv6 on untrusted network interfaces to avoid the impact of the vulnerability. Additionally, configuring the kernel to drop all IPv6 fragments can prevent exploitation of the bug with the caveat of dropping legitimate IPv6 fragments.

Long-Term Security Practices

Implementing firewall rules and enabling scrubbing and fragment reassembly on untrusted interfaces through tools like pf(4) firewall can enhance security against such vulnerabilities in the long term.

Patching and Updates

It is crucial for FreeBSD users to apply the necessary patches and updates provided by FreeBSD to address the CVE-2023-3107 vulnerability. Stay informed about security advisories and apply patches promptly to ensure system security.