EUVD-2023-31017

Comprehensive Technical Analysis of EUVD-2023-31017

1. Vulnerability Assessment and Severity Evaluation

The vulnerability identified in EUVD-2023-31017 pertains to a stack overflow in the Tenda AX3 router firmware version V16.03.12.11. The stack overflow occurs via the shareSpeed parameter in the /goform/WifiGuestSet endpoint. 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:

• AV:N (Attack Vector: Network): The vulnerability is exploitable remotely over the network.
• AC:L (Attack Complexity: Low): The attack requires minimal skill or resources.
• PR:N (Privileges Required: None): No privileges are required to exploit the vulnerability.
• UI:N (User Interaction: None): No user interaction is required.
• S:U (Scope: Unchanged): The vulnerability does not change the security scope.
• C:H (Confidentiality: High): The vulnerability has a high impact on confidentiality.
• I:H (Integrity: High): The vulnerability has a high impact on integrity.
• A:H (Availability: High): The vulnerability has a high impact on availability.

2. Potential Attack Vectors and Exploitation Methods

The stack overflow vulnerability can be exploited by sending a specially crafted request to the /goform/WifiGuestSet endpoint with a malicious shareSpeed parameter. This could lead to arbitrary code execution, allowing an attacker to:

• Execute Remote Code: Gain control over the device and execute arbitrary commands.
• Denial of Service (DoS): Crash the device, making it unavailable to legitimate users.
• Data Exfiltration: Access sensitive information stored on the device.

3. Affected Systems and Software Versions

The vulnerability specifically affects Tenda AX3 routers running firmware version V16.03.12.11. It is crucial to identify all devices within the network that use this firmware version to assess the scope of the risk.

4. Recommended Mitigation Strategies

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

• Firmware Update: Immediately update the firmware to a version that addresses this vulnerability. Contact Tenda for the latest firmware updates.
• Network Segmentation: Isolate the affected devices from critical network segments to limit potential damage.
• Firewall Rules: Implement strict firewall rules to restrict access to the /goform/WifiGuestSet endpoint.
• Intrusion Detection Systems (IDS): Deploy IDS to monitor for suspicious activity targeting the vulnerable endpoint.
• Regular Audits: Conduct regular security audits and vulnerability assessments to identify and address similar issues proactively.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to European organizations and individuals using Tenda AX3 routers. Given the critical nature of the vulnerability, it could be exploited by malicious actors to compromise network security, leading to data breaches, service disruptions, and potential financial losses. The widespread use of such devices in both residential and commercial settings amplifies the potential impact.

6. Technical Details for Security Professionals

Exploitation Details:

• Endpoint: /goform/WifiGuestSet
• Parameter: shareSpeed
• Exploit Method: Craft a request with a malicious shareSpeed value to trigger the stack overflow.

Detection:

• Log Analysis: Monitor logs for unusual activity related to the /goform/WifiGuestSet endpoint.
• Network Traffic: Use network monitoring tools to detect anomalous traffic patterns targeting the vulnerable endpoint.

Patching:

• Firmware Update: Ensure all Tenda AX3 routers are updated to the latest firmware version provided by the vendor.
• Configuration Management: Regularly review and update device configurations to ensure they adhere to security best practices.

References:

• GitHub Repository: GitHub Link
• CVE ID: CVE-2023-27239
• GSD ID: GSD-2023-27239

By following these recommendations and staying vigilant, organizations can significantly reduce the risk posed by this vulnerability and enhance their overall cybersecurity posture.