CVE-2024-3596
Description
A vulnerability in the RADIUS (Remote Authentication Dial-In User Service) protocol allows attackers to forge authentication responses when the Message-Authenticator attribute is not enforced. This issue arises from a cryptographically insecure integrity check using MD5, enabling attackers to spoof UDP-based RADIUS response packets. This can result in unauthorized access by modifying an Access-Reject response to an Access-Accept response, thereby compromising the authentication process.
Statement
This vulnerability is of Important severity due to its ability to undermine the fundamental security mechanisms of RADIUS-based authentication systems. By exploiting the weak MD5 integrity check, an attacker can forge RADIUS responses, effectively bypassing authentication controls and gaining unauthorized access to network resources. This poses a significant threat to environments relying on RADIUS for user and device authentication, particularly those lacking enforced Message-Authenticator attributes or TLS/DTLS encryption.
There are several preconditions for this attack to be possible:
- An attacker needs man-in-the-middle network access between the RADIUS client and server
- The client and server must be using RADIUS/UDP to communicate
- The attacker needs to be able to trigger a RADIUS client Access-Request ( for example the client is using PAP authentication)
Due to these attack surface limitations, the impact is rated Important. Within Red Hat offerings, this impacts the FreeRADIUS package. This flaw allows a local, unauthenticated attacker to conduct a man-in-the-middle attack to log in as a third party without knowing their credentials. Servers using Extensible Authentication Protocol (EAP) with required Message-Authenticator attributes or those employing TLS/DTLS encryption are not affected.
Mitigation
Disable the use of RADIUS/UDP and RADIUS/TCP.
RADIUS/TLS or RADIUS/DTLS should be used.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 9 | 9 | 9 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | High | High |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Changed | Changed | Changed |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Modify Application Data; Other
Integrity checks usually use a secret key that helps authenticate the data origin. Skipping integrity checking generally opens up the possibility that new data from an invalid source can be injected.
Integrity,Other
Technical Impact: Other
Data that is parsed and used may be corrupted.
Non-Repudiation,Other
Technical Impact: Hide Activities; Other
Without a checksum check, it is impossible to determine if any changes have been made to the data after it was sent.
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