July 9, 2024 at 03:51PM
Blast-RADIUS is an authentication bypass in the RADIUS/UDP protocol, allowing attackers to breach networks via MD5 collision attacks. It affects numerous networked devices and poses a significant threat. The exploit manipulates server responses to gain admin privileges without brute force or credential theft. To defend against it, network operators should upgrade to RADIUS over TLS, switch to “multihop” RADIUS deployments, and isolate RADIUS traffic.
Based on the meeting notes, the key takeaways are:
1. A vulnerability in the RADIUS protocol, known as Blast-RADIUS, allows attackers to execute a man-in-the-middle MD5 collision attack, enabling them to breach networks and devices without stealing credentials.
2. The exploit, identified as CVE-2024-3596, manipulates server responses by injecting arbitrary protocol attributes, granting the attacker admin privileges on RADIUS devices.
3. The attack enables the attacker to escalate privileges and gain access to network devices and services without brute forcing passwords or stealing credentials.
4. The researchers were able to demonstrate a chosen-prefix MD5 collision attack within 3 to 6 minutes, longer than the typical RADIUS timeouts, but optimization could significantly reduce this time.
5. To defend against this attack, network operators are advised to consider upgrading to RADIUS over TLS (RADSEC), switching to “multihop” RADIUS deployments, and isolating RADIUS traffic from internet access using restricted-access management VLANs or TLS/ IPsec tunneling.
These takeaways should provide a clear understanding of the Blast-RADIUS vulnerability and the recommended best practices for defending against it.