Escaping the Blast RADIUS

In the latest episode of "The Other Side of the Firewall" podcast, Ryan Williams Sr., Shannon Tynes, Chris Abacon, and Daniel Acevedo discuss a critical issue that has significant implications for cybersecurity professionals across the board. We discussed an article by Dan Goodin from Ars Technica about a newly discovered vulnerability, dubbed the "Blast Radius Attack," which targets a 30-year-old protocol widely used in networks everywhere. This conversation is particularly relevant for those of us in the field, whether you’re a seasoned CISO or just breaking into cybersecurity.

The vulnerability exploits the User Datagram Protocol (UDP) used in RADIUS (Remote Authentication Dial-In User Service), which is a networking protocol providing centralized Authentication, Authorization, and Accounting (AAA) management for users who connect and use a network service. The protocol's history stretches back to 1992, and despite its age, it remains integral in many modern networking environments, from DoD installations to home ISPs and corporate infrastructures.

The Nature of the Attack

The Blast Radius Attack is primarily a man-in-the-middle exploit targeting the MD5 hash used in RADIUS. As Chris elaborated during our discussion, "The attack focuses on the UDP aspect of RADIUS, exploiting the MD5 hashing algorithm which is quite outdated. The attacker can intercept and manipulate the data packets between the RADIUS client (like a network switch) and the RADIUS server, ultimately gaining unauthorized access."

This attack is particularly concerning because of the ubiquity of RADIUS. It’s used in numerous devices and services, including VPNs, Wi-Fi authentication, and even some 5G networks. Shannon pointed out the pervasive use of this protocol: "You see this everywhere in the DoD and in various communication devices. With such wide usage, the impact of this vulnerability could be far-reaching."

Implications for Network Security

The discovery of this vulnerability underscores the need for vigilance and proactive measures in network security. For organizations using RADIUS, especially with UDP and MD5, this is a wake-up call. The immediate steps should include reviewing and potentially overhauling the authentication methods used in their network infrastructures.

Daniel highlighted the importance of a comprehensive approach to this issue: "This is an adversary-in-the-middle attack, which means it requires the attacker to already have access to the network. If they do, and if your RADIUS setup isn't secured against this type of exploit, the potential for damage is significant."

Steps for Mitigation

There are several steps organizations can take to mitigate this risk:

1. Upgrade Authentication Protocols: Moving away from MD5 to more secure hashing algorithms like SHA-256 or implementing multi-factor authentication can significantly reduce the risk.
2. Network Segmentation: Ensuring that sensitive data flows are segmented and protected by robust perimeter defenses can help contain potential breaches.
3. Regular Audits: Conducting regular security audits to identify and patch vulnerabilities promptly.

This episode is a reminder of the constant evolution of cybersecurity threats and the need for continuous learning and adaptation. The full discussion and technical details are available in the podcast episode, where we break down the specifics and discuss practical steps you can take to protect your networks.

Stay informed, stay secure, and as always, keep pushing the boundaries of what's possible in cybersecurity.

Thank you for reading and stay tuned for more episodes of The Other Side of the Firewall podcast on Monday, Tuesday, Wednesday, and Fridays, as well as, the Ask A CISSP podcast every Thursday. Please like, share, and, subscribe.

Stay safe, stay secure!

Ryan is a retired Air Force veteran who brings over 20 years of experience in network infrastructure, project management, and cybersecurity consulting to his current role at BuddoBot. Buddobot's mission is to support national security by transforming, empowering, and educating organizations to shift from reactive, diluted, automated, and high-cost IT and security practices to proactive, effective solutions that fortify their security.

Shannon, also a retired Air Force veteran, has more than two decades of expertise in network security and vulnerability management. He now serves as an Information System Security Officer (ISSO) for the U.S. Space Force, where he continues to enhance national security protocols.

Chris, a Navy veteran with over ten years in IT, information assurance, and risk management, currently works at CompliancePoint. His roles include vCISO, RMF assessor, and consultant, focusing on enhancing data security and privacy for various organizations.

Daniel is an Air Force veteran with over 15 years of combined experience in IT, cybersecurity, information assurance, and government risk compliance. He has held various roles, including IT administrator, cybersecurity engineer, senior information system security manager, and currently serves as a senior security consultant for Booz Allen Hamilton. In this latest role, Daniel leverages his expertise to address unique and complex challenges in the cyber and IT domains, enhancing his customers' capabilities.