Cisco Switch Zero-Day (CVE-2024-20399) Seen Exploited in the Wild by Chinese Threat Actor

Cisco, the global leader in networking technology, has recently addressed a significant security vulnerability in its Nexus operating system (NX-OS) software. The medium-severity zero-day flaw, CVE-2024-20399, affects Cisco’s widely used Nexus switches’ command line interface (CLI).

Vulnerability Details and Potential Impact

The vulnerability could allow an attacker with valid administrator credentials to execute arbitrary commands on the underlying Linux operating system of Nexus devices. Cisco’s July 1 advisory emphasized that successful exploitation grants root privileges, potentially enabling attackers to:

• Access sensitive data
• Control critical systems
• Modify important files

This level of access poses a severe threat to network integrity and data security for organizations relying on Cisco Nexus infrastructure.

Discovery and Exploitation in the Wild

Cisco’s Product Security Incident Response Team learned of the vulnerability’s active exploitation in April, thanks to researchers at cybersecurity firm Sygnia. The discovery was part of a larger forensic investigation into a Chinese cyber espionage operation by a threat actor, “Velvet Ant.”

Velvet Ant: A Persistent Threat

Sygnia’s research revealed that Velvet Ant had previously succeeded in maintaining persistence within a large organization’s corporate network for three years. The threat actor achieved this by exploiting flaws in legacy F5 BigIP load balancers, demonstrating their sophisticated capabilities and long-term approach to cyber espionage.

The discovery of this zero-day vulnerability in Cisco’s NX-OS has raised concerns among cybersecurity experts:

Supply Chain Risks

Narayana Pappu, CEO of Zendata, highlighted the significant supply chain risks associated with the vulnerability: “Cisco Nexus switches are the backbone of data center networks, creating substantial supply chain risks for many types of companies.”

Insider Threats and Zero Trust

Venky Raju, Field CTO at ColorTokens, emphasized the potential for attackers to become “insiders” within enterprise networks:

“Most businesses have not implemented adequate safeguards against insider threats, which presents a significant risk. This is a stark reminder to adopt a zero-trust mindset and implement micro-segmentation to minimize lateral movement across the entire network.”

Recommendations for Organizations

In light of this vulnerability and the ongoing threat from sophisticated actors like Velvet Ant, organizations should consider the following actions:

1. Apply Cisco’s security patch immediately to affected NX-OS devices
2. Implement robust detection and monitoring capabilities
3. Adopt a zero-trust security model
4. Deploy micro-segmentation to limit lateral movement within networks
5. Regularly audit and update access controls, especially for administrative accounts
6. Enhance supply chain security measures, particularly for critical network infrastructure