CVE-2023-20047 : Vulnerability Insights and Analysis

This CVE-2023-20047 advisory was published by Cisco on January 19, 2023. The vulnerability affects Cisco Webex Room Phone and Cisco Webex Share devices, potentially allowing an unauthenticated attacker to cause a denial of service (DoS) condition by exploiting the Link Layer Discovery Protocol (LLDP) feature.

Understanding CVE-2023-20047

This vulnerability pertains to insufficient resource allocation in the LLDP feature of Cisco Webex Room Phone and Cisco Webex Share devices. An attacker, in close proximity to the affected device, could exploit this weakness to send crafted LLDP traffic, leading to memory exhaustion and a crash in the LLDP process.

What is CVE-2023-20047?

CVE-2023-20047 is a vulnerability in the LLDP feature of Cisco Webex Room Phone and Cisco Webex Share devices. It allows an adjacent attacker to initiate a DoS attack by overwhelming the device's memory resources, potentially disrupting inbound and outbound calling functionalities.

The Impact of CVE-2023-20047

The impact of this vulnerability can result in a significant disruption to the affected device's operation, particularly if it is configured to support LLDP exclusively. A successful exploit could lead to a crash in the LLDP process, necessitating a manual restart to restore operational status.

Technical Details of CVE-2023-20047

This section delves into the specifics of the vulnerability, focusing on the vulnerability description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The vulnerability stems from inadequacies in resource allocation within the LLDP feature of Cisco Webex Room Phone and Cisco Webex Share devices. Attackers can exploit this weakness by sending malicious LLDP traffic, causing memory exhaustion and subsequent crashes in the LLDP process.

Affected Systems and Versions

The affected systems include Cisco Webex Room Phone versions 1.1.0, 1.2.0, 1.2.0SR1, and 1.2.0SR2. These versions are susceptible to the vulnerability if the devices are configured to support LLDP exclusively.

Exploitation Mechanism

To exploit CVE-2023-20047, an attacker must be in close proximity to the target device and send specifically crafted LLDP traffic. This malicious traffic triggers a sequence of events leading to memory resource exhaustion and a subsequent crash in the LLDP process.

Mitigation and Prevention

Protecting against CVE-2023-20047 involves taking immediate steps to mitigate its impact, adopting long-term security practices, and ensuring systems are regularly updated with patches.

Immediate Steps to Take

Immediate actions to mitigate the vulnerability include monitoring network traffic for any signs of LLDP abuse, restricting physical access to vulnerable devices, and implementing network segmentation to limit the scope of potential attacks.

Long-Term Security Practices

Implementing network security best practices, conducting regular security assessments, staying informed about emerging threats, and educating personnel on security awareness are essential for long-term protection against vulnerabilities like CVE-2023-20047.

Patching and Updates

Cisco may release patches or updates to address CVE-2023-20047. It is crucial for organizations to stay informed about these releases and apply them promptly to mitigate the risk of exploitation and safeguard their devices from potential attacks.