EUVD-2023-28115

Comprehensive Technical Analysis of EUVD-2023-28115

1. Vulnerability Assessment and Severity Evaluation

The vulnerability described in EUVD-2023-28115 pertains to a client-side rate limit issue in the Connectize AC21000 G6 641.139.1.1256 firmware. This flaw allows attackers to bypass rate-limiting mechanisms, enabling them to perform brute force attacks to escalate privileges. The CVSS (Common Vulnerability Scoring System) base score of 9.8 indicates a critical severity level. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H breaks down as follows:

• Attack Vector (AV): Network (N) - The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low (L) - The attack requires minimal skill or resources.
• Privileges Required (PR): None (N) - No special privileges are needed to exploit the vulnerability.
• User Interaction (UI): None (N) - No user interaction is required for the attack to succeed.
• Scope (S): Unchanged (U) - The vulnerability does not affect other security scopes.
• Confidentiality (C): High (H) - The vulnerability results in a complete loss of confidentiality.
• Integrity (I): High (H) - The vulnerability results in a complete loss of integrity.
• Availability (A): High (H) - The vulnerability results in a complete loss of availability.

2. Potential Attack Vectors and Exploitation Methods

The primary attack vector involves exploiting the lack of effective rate limiting on the client side. Attackers can:

• Brute Force Attacks: Perform rapid, repeated authentication attempts to guess valid credentials.
• Privilege Escalation: Once valid credentials are obtained, attackers can escalate their privileges to gain administrative access.
• Denial of Service (DoS): Flood the system with authentication requests, potentially leading to a denial of service condition.

3. Affected Systems and Software Versions

The vulnerability specifically affects the Connectize AC21000 G6 dual-band gigabit WiFi router running firmware version 641.139.1.1256. Other versions of the firmware may also be affected, but this has not been confirmed.

4. Recommended Mitigation Strategies

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

• Firmware Update: Immediately update the router firmware to the latest version provided by the vendor.
• Rate Limiting: Implement additional rate-limiting mechanisms on the network to prevent brute force attacks.
• Strong Authentication: Enforce strong, complex passwords and consider implementing multi-factor authentication (MFA).
• Network Segmentation: Segment the network to limit the attack surface and isolate critical systems.
• Monitoring and Alerts: Implement monitoring tools to detect and alert on unusual authentication attempts or failed login attempts.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to European organizations and individuals using the affected router model. Given the critical nature of the vulnerability, it could lead to widespread compromise of network security, data breaches, and potential disruption of services. The European Union's cybersecurity agencies, such as ENISA, should issue advisories and work with vendors to ensure timely patching and mitigation.

6. Technical Details for Security Professionals

• Vulnerability Identification: The vulnerability is identified by CVE-2023-24051 and GSD-2023-24051.
• Technical Advisory: Refer to the NCC Group's technical advisory for detailed information on the vulnerability and associated CVEs: NCC Group Advisory.
• Mitigation Steps:
  • Patch Management: Ensure that all devices are running the latest firmware.
  • Network Security: Implement robust network security measures, including firewalls, intrusion detection systems (IDS), and intrusion prevention systems (IPS).
  • User Education: Educate users on the importance of strong passwords and the risks associated with brute force attacks.

By addressing these points, organizations can significantly reduce the risk posed by this vulnerability and enhance their overall cybersecurity posture.