CVE-2023-28840 : What You Need to Know

This article delves into the details of CVE-2023-28840, focusing on an encrypted overlay network vulnerability in the Moby container framework.

Understanding CVE-2023-28840

CVE-2023-28840 highlights an issue within the dockerd daemon of the Moby container framework, potentially exposing an unauthenticated encrypted overlay network.

What is CVE-2023-28840?

Moby, an open-source container framework developed by Docker Inc., includes the

dockerd

daemon, crucial to the functioning of containers. The vulnerability affects the overlay network driver, which facilitates communication between containers and services across a cluster.

The Impact of CVE-2023-28840

The vulnerability poses a high risk, with a CVSS v3.1 base score of 7.5 (High severity) due to potential unauthorized access to confidential information and the possibility of a Denial of Service (DoS) attack.

Technical Details of CVE-2023-28840

This section provides insight into the vulnerability's technical aspects, including its description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability in the encrypted overlay network exposes the Moby container framework to attacks, allowing unauthorized access to network traffic and potential DoS attacks.

Affected Systems and Versions

The vulnerability impacts Moby versions >= 1.12.0 and < 20.10.24, as well as versions >= 23.0.0 and < 23.0.3. Users of these versions are encouraged to take immediate action to mitigate the risk.

Exploitation Mechanism

By exploiting this vulnerability, an attacker could inject arbitrary Ethernet frames into the network, bypassing security measures and potentially launching a DoS attack or gaining unauthorized access to sensitive data.

Mitigation and Prevention

To address CVE-2023-28840, users and administrators should take immediate steps to secure their systems and prevent any potential exploitation of the vulnerability.

Immediate Steps to Take

Close the VXLAN port to incoming traffic at the Internet boundary to prevent unauthorized injections and ensure the

xt_u32

kernel module is available on all nodes of the Swarm cluster for additional protection.

Long-Term Security Practices

Implement regular security updates and patches, conduct security audits, and enforce strict network segmentation and access controls to enhance overall system security.

Patching and Updates

Patches addressing CVE-2023-28840 are available in Moby releases 23.0.3 and 20.10.24. Users are advised to update their systems to the patched versions to mitigate the vulnerability effectively.