EUVD-2024-21153

Comprehensive Technical Analysis of EUVD-2024-21153

1. Vulnerability Assessment and Severity Evaluation

The vulnerability identified in EUVD-2024-21153 pertains to Rejetto HTTP File Server (HFS) versions up to and including 2.3m. This vulnerability is classified as a template injection vulnerability, which allows a remote, unauthenticated attacker to execute arbitrary commands on the affected system by sending a specially crafted HTTP request.

Severity Evaluation:

• Base Score: 9.8 (Critical)
• Base Score Version: CVSS:3.1
• Base Score Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

The CVSS score of 9.8 indicates a critical vulnerability due to the following factors:

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)

This high severity is due to the potential for unauthenticated remote code execution (RCE), which can lead to complete system compromise.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Remote Exploitation: An attacker can exploit this vulnerability over the network without needing any authentication or user interaction.
• HTTP Requests: The attacker sends a specially crafted HTTP request to the vulnerable HFS server, which triggers the template injection vulnerability.

Exploitation Methods:

• Template Injection: The attacker injects malicious code into the template processing mechanism of the HFS server.
• Command Execution: The injected code allows the attacker to execute arbitrary commands on the server, leading to full control over the system.

3. Affected Systems and Software Versions

Affected Software:

• Rejetto HTTP File Server (HFS) versions up to and including 2.3m.

Affected Systems:

• Any system running the vulnerable versions of Rejetto HFS, including but not limited to:
  • Windows Servers
  • Linux Servers (if running via Wine or other compatibility layers)
  • Virtual Machines and Containers running the affected software

4. Recommended Mitigation Strategies

Immediate Actions:

• Upgrade/Patch: Upgrade to a supported version of Rejetto HFS if available. As of the CVE assignment date, version 2.3m is no longer supported, so consider alternative file server solutions.
• Disable Service: If an upgrade is not possible, disable the Rejetto HFS service until a secure alternative is implemented.
• Network Segmentation: Isolate the affected systems from the network to limit potential attack vectors.

Long-Term Mitigations:

• Regular Patching: Implement a regular patching and update schedule for all software.
• Security Monitoring: Enhance monitoring for suspicious activities and anomalies in network traffic.
• Access Controls: Implement strict access controls and authentication mechanisms for all services.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to organizations within the European Union that rely on Rejetto HFS for file sharing and management. The potential for unauthenticated RCE can lead to data breaches, system compromises, and disruptions in service, affecting both public and private sectors.

Regulatory Implications:

• GDPR Compliance: Organizations must ensure that personal data is protected, and any breach due to this vulnerability could result in GDPR violations and subsequent penalties.
• NIS Directive: Critical infrastructure providers must adhere to the Network and Information Systems (NIS) Directive, ensuring robust cybersecurity measures are in place.

6. Technical Details for Security Professionals

Vulnerability Details:

• CVE ID: CVE-2024-23692
• GSD ID: GSD-2024-23692
• EPSS Score: 94 (indicating a high likelihood of exploitation)

References:

• VulnCheck Advisory
• Mohemiv Analysis
• Metasploit Framework Pull Request

Technical Recommendations:

• Intrusion Detection: Implement intrusion detection systems (IDS) to monitor for suspicious HTTP requests targeting the HFS server.
• Log Analysis: Regularly review server logs for any unusual activities or patterns indicative of exploitation attempts.
• Incident Response: Develop and maintain an incident response plan tailored to address RCE vulnerabilities, including steps for containment, eradication, and recovery.

Conclusion: The critical nature of this vulnerability necessitates immediate action from organizations using Rejetto HFS. By following the recommended mitigation strategies and maintaining vigilant security practices, organizations can significantly reduce the risk of exploitation and protect their systems and data.