EUVD-2023-35562

Comprehensive Technical Analysis of EUVD-2023-35562

1. Vulnerability Assessment and Severity Evaluation

The vulnerability EUVD-2023-35562, also known as CVE-2023-31247, is a memory corruption issue in the HTTP Server Host header parsing functionality of Weston Embedded uC-HTTP v3.01.01. This vulnerability allows an attacker to execute arbitrary code by sending a specially crafted network packet. The CVSS (Common Vulnerability Scoring System) base score of 9.0 indicates a critical severity level. The vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H breaks down as follows:

• Attack Vector (AV): Network (N) - The vulnerability is exploitable over the network.
• Attack Complexity (AC): High (H) - The attack requires specific conditions or knowledge.
• Privileges Required (PR): None (N) - No privileges are required to exploit the vulnerability.
• User Interaction (UI): None (N) - No user interaction is required.
• Scope (S): Changed (C) - The vulnerability can affect resources beyond the security scope managed by the security authority.
• Confidentiality (C): High (H) - There is a high impact on confidentiality.
• Integrity (I): High (H) - There is a high impact on integrity.
• Availability (A): High (H) - There is a high impact on availability.

2. Potential Attack Vectors and Exploitation Methods

The primary attack vector is through network communication. An attacker can craft a malicious HTTP packet with a specially designed Host header to exploit the memory corruption vulnerability. This can be achieved through:

• Direct Network Attacks: Sending the malicious packet directly to the vulnerable HTTP server.
• Man-in-the-Middle (MitM) Attacks: Intercepting and modifying legitimate HTTP requests to include the malicious Host header.
• Phishing and Social Engineering: Tricking users into visiting a malicious website that sends the crafted packet to the server.

3. Affected Systems and Software Versions

The vulnerability specifically affects:

• Weston Embedded uC-HTTP v3.01.01

Additionally, the ENISA ID Product list indicates that the following products and versions are affected:

• Gecko Platform v4.3.1.0
• Cesium NET v3.07.01
• uC-HTTP v3.01.01

The ENISA ID Vendor list includes:

• Weston Embedded
• Silicon Labs

4. Recommended Mitigation Strategies

To mitigate the risk associated with this vulnerability, the following strategies are recommended:

• Patch Management: Apply the latest patches and updates provided by Weston Embedded and other affected vendors.
• Network Segmentation: Isolate vulnerable systems from critical networks to limit the attack surface.
• Intrusion Detection Systems (IDS): Deploy IDS to monitor network traffic for suspicious activities.
• Firewall Configuration: Implement strict firewall rules to block unauthorized access to the HTTP server.
• Input Validation: Enhance input validation mechanisms to filter out malicious Host headers.
• Regular Audits: Conduct regular security audits and vulnerability assessments.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to organizations using the affected software, particularly those in critical infrastructure sectors such as healthcare, finance, and energy. The potential for remote code execution can lead to data breaches, service disruptions, and unauthorized access to sensitive information. Given the critical CVSS score, this vulnerability underscores the need for robust cybersecurity measures and continuous monitoring within the European cybersecurity landscape.

6. Technical Details for Security Professionals

Vulnerability Details:

• Type: Memory Corruption
• Location: HTTP Server Host header parsing functionality
• Impact: Arbitrary code execution

Exploitation Steps:

1. Craft Malicious Packet: Create an HTTP packet with a specially designed Host header.
2. Send Packet: Transmit the packet to the vulnerable HTTP server.
3. Trigger Vulnerability: The server processes the malicious Host header, leading to memory corruption and potential code execution.

Detection and Response:

• Log Analysis: Monitor server logs for unusual activities or error messages related to Host header parsing.
• Behavioral Analysis: Use behavioral analysis tools to detect anomalous behavior indicative of exploitation.
• Incident Response: Have an incident response plan in place to quickly address any detected exploitation attempts.

References:

• Talos Intelligence Report: TALOS-2023-1746

By addressing this vulnerability promptly and implementing the recommended mitigation strategies, organizations can significantly reduce the risk of exploitation and protect their critical assets.