CVE-2024-3596: FreeRADIUS Auth Bypass Vulnerability

CVE-2024-3596 Overview

RADIUS Protocol under RFC 2865 is susceptible to forgery attacks by a local attacker who can modify any valid Response (Access-Accept, Access-Reject, or Access-Challenge) to any other response using a chosen-prefix collision attack against the MD5 Response Authenticator signature.

Critical Impact
The vulnerability allows attackers to intercept and modify authentication responses, leading to unauthorized access or denial of service.

Affected Products

freeradius freeradius
broadcom brocade_sannav
broadcom fabric_operating_system
sonicwall sonicos

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to freeradius
Not Available - CVE CVE-2024-3596 assigned
Not Available - freeradius releases security patch
2024-07-09 - CVE CVE-2024-3596 published to NVD
2025-11-04 - Last updated in NVD database

Technical Details for CVE-2024-3596

Vulnerability Analysis

The vulnerability resides in the RADIUS protocol's use of the MD5 Response Authenticator. Attackers can leverage chosen-prefix collisions in MD5 hashes to forge authentication responses, thereby circumventing security measures intended to enforce network access control.

Root Cause

A weak cryptographic mechanism in the RADIUS protocol, specifically the MD5 hashing algorithm, which is prone to collision attacks.

Attack Vector

Network-based exploitation where the attacker has local access and can intercept or modify RADIUS packets.

bash

# Example exploitation code (sanitized)
import hashlib

# Simulate MD5 collision attack
fake_response = b"Fake-Response"
legit_response = b"Legit-Response"

# Forgery
if hashlib.md5(fake_response).digest() == hashlib.md5(legit_response).digest():
    print("Potential Forgery Detected")

Detection Methods for CVE-2024-3596

Indicators of Compromise

Unexpected RADIUS access requests
Anomalies in RADIUS access logs
Discrepancies in user authentication records

Detection Strategies

Utilize packet inspection and anomaly detection systems to monitor RADIUS traffic for unusual patterns indicative of forgery or collision attempts.

Monitoring Recommendations

Implement security information and event management (SIEM) solutions to track RADIUS protocol usage and correlate it with known attack patterns.

How to Mitigate CVE-2024-3596

Immediate Actions Required

Disable reliance on vulnerable MD5 hashing in RADIUS
Implement stronger hash functions like SHA-256
Restrict network access to RADIUS servers

Patch Information

As of the last update, no specific patch information is available. Vendors are encouraged to update cryptographic dependencies.

Workarounds

Update RADIUS configurations to use stronger cryptographic methods and consider using more secure protocols like EAP-TLS.