CVE-2021-1586 Explained : Impact and Mitigation

A vulnerability has been identified in the Multi-Pod or Multi-Site network configurations for Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode. This vulnerability in Cisco NX-OS System Software in ACI Mode could allow an unauthenticated, remote attacker to create a denial of service (DoS) situation by unexpectedly restarting the device. The root cause of this vulnerability lies in the improper sanitization of TCP traffic sent to a specific port on the affected device.

Understanding CVE-2021-1586

This section will provide insights into the nature of CVE-2021-1586.

What is CVE-2021-1586?

CVE-2021-1586 refers to a vulnerability in the Multi-Pod or Multi-Site configurations for Cisco Nexus 9000 Series Fabric Switches in ACI mode. The flaw could allow a remote attacker to trigger a DoS condition by sending crafted TCP data to a specific port.

The Impact of CVE-2021-1586

The impact of this CVE is rated as 'HIGH' with a CVSS base score of 8.6. An attacker exploiting this vulnerability could cause a targeted device to restart unexpectedly, leading to a complete denial of service.

Technical Details of CVE-2021-1586

This section will delve into the technical aspects of CVE-2021-1586.

Vulnerability Description

The vulnerability arises due to the lack of proper sanitization of TCP traffic on specific ports on affected Cisco Nexus 9000 Series Fabric Switches in ACI mode. An attacker can exploit this by sending manipulated TCP data to a specific port listening on a public-facing IP address, resulting in device restarts.

Affected Systems and Versions

The affected product is the Cisco NX-OS System Software in ACI Mode, with all versions being susceptible to this vulnerability.

Exploitation Mechanism

Exploitation of this vulnerability involves the attacker sending crafted TCP data to a port on the device configured for Multi-Pod or Multi-Site network setups, causing an unexpected device restart.

Mitigation and Prevention

Learn how to prevent and mitigate the risks associated with CVE-2021-1586.

Immediate Steps to Take

It is recommended to apply official patches provided by Cisco to fix this vulnerability. Network administrators should also implement proper firewall rules to restrict access to the vulnerable ports.

Long-Term Security Practices

Regular security assessments, network monitoring, and timely patch management are essential for long-term security preparedness.

Patching and Updates

Stay updated with security bulletins from Cisco and promptly apply patches or updates to secure your network infrastructure.