CVE-2023-24513 : Security Advisory and Response

A denial-of-service vulnerability has been identified in Arista CloudEOS that could potentially be exploited through the Software Forwarding Engine (Sfe), leading to a disruption in forwarding traffic. This issue affects specific versions of Arista EOS and requires sending malformed packets to the switch.

Understanding CVE-2023-24513

This section delves deeper into the details of CVE-2023-24513, shedding light on the vulnerability, its impact, and the recommended mitigation strategies.

What is CVE-2023-24513?

CVE-2023-24513 represents a size check bypass issue in the Software Forwarding Engine (Sfe) on affected platforms running Arista CloudEOS. By exploiting this vulnerability, an attacker could trigger buffer over-reads, potentially causing a recomputation of the TCP checksum.

The Impact of CVE-2023-24513

The exploitation of CVE-2023-24513 could result in a denial of service attack on the switch by flooding it with malformed packets. This act leads to a leakage of packet buffers and, upon receiving a sufficient volume of such packets, the switch might cease forwarding traffic altogether.

Technical Details of CVE-2023-24513

In this section, we will explore the vulnerability description, affected systems and versions, as well as the exploitation mechanism associated with CVE-2023-24513.

Vulnerability Description

The vulnerability arises due to a size check bypass issue in the Software Forwarding Engine, enabling unauthorized parties to trigger buffer over-reads and potentially disrupt the switch's normal operation.

Affected Systems and Versions

Arista EOS versions 4.29.0 to 4.29.1F, 4.28.0 to 4.28.5M, 4.27.0 to 4.27.8M, and 4.26.0 to 4.26.9M are confirmed to be affected by CVE-2023-24513.

Exploitation Mechanism

To exploit this vulnerability, the switch must be configured to run the Software Forwarding Engine (Sfe), which is the default setting on CloudEOS platforms.

Mitigation and Prevention

To address CVE-2023-24513, immediate steps need to be taken along with the implementation of long-term security practices. Patching and updates are crucial for safeguarding systems against this vulnerability.

Immediate Steps to Take

Unfortunately, there is no known mitigation or workaround for CVE-2023-24513. Therefore, the best course of action is to apply the recommended solutions promptly to remediate the issue.

Long-Term Security Practices

In the long run, ensuring that systems are regularly updated with the latest software versions and security patches is essential in preventing potential vulnerabilities like CVE-2023-24513 from being exploited.

Patching and Updates

Arista recommends upgrading to the remediated software versions listed below to address CVE-2023-24513:

For 4.29.x train: 4.29.2F and later releases
For 4.28.x train: 4.28.6M and later releases
For 4.27.x train: 4.27.9M and later releases
For 4.26.x train: 4.26.10M and later releases

Additionally, hotfixes are available to mitigate CVE-2023-24513, with specific files applicable to different release versions within each train. Installation of these hotfixes may lead to temporary disruptions in forwarding traffic.