EUVD-2023-37713

Comprehensive Technical Analysis of EUVD-2023-37713

1. Vulnerability Assessment and Severity Evaluation

The EUVD entry EUVD-2023-37713 describes a command injection vulnerability in the TOTOLink A7100RU V7.4cu.2313_B20191024 firmware. This vulnerability is present in the staticGw parameter at the /setting/setWanIeCfg 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:

• 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 change the security scope.
• Confidentiality (C): High (H) - The vulnerability can result in a complete loss of confidentiality.
• Integrity (I): High (H) - The vulnerability can result in a complete loss of integrity.
• Availability (A): High (H) - The vulnerability can result in a complete loss of availability.

2. Potential Attack Vectors and Exploitation Methods

The command injection vulnerability can be exploited by sending specially crafted requests to the /setting/setWanIeCfg endpoint with malicious input in the staticGw parameter. Potential attack vectors include:

• Remote Code Execution (RCE): An attacker can inject arbitrary commands that the device will execute, leading to full control over the device.
• Data Exfiltration: By injecting commands to read sensitive files or configurations, an attacker can exfiltrate confidential information.
• Denial of Service (DoS): An attacker can inject commands to disrupt the normal operation of the device, leading to a denial of service.

3. Affected Systems and Software Versions

The vulnerability specifically affects the TOTOLink A7100RU router with firmware version V7.4cu.2313_B20191024. Other versions of the firmware or different models of TOTOLink routers 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 firmware to a version that addresses this vulnerability. If no update is available, consider using an alternative router model.
• Network Segmentation: Isolate the affected device on a separate network segment to limit potential damage.
• Access Control: Implement strict access controls to limit who can access the router's management interface.
• Monitoring and Logging: Enable logging and monitoring to detect any suspicious activity related to the /setting/setWanIeCfg endpoint.
• Firewall Rules: Implement firewall rules to restrict access to the router's management interface from untrusted networks.

5. Impact on European Cybersecurity Landscape

The presence of this vulnerability in a widely used router model poses a significant risk to the European cybersecurity landscape. Routers are critical components of both home and enterprise networks, and a compromised router can lead to further attacks on connected devices and networks. The high CVSS score and the ease of exploitation make this vulnerability particularly concerning.

6. Technical Details for Security Professionals

For security professionals, the following technical details are pertinent:

• Exploit Code: The vulnerability can be exploited by sending a crafted HTTP request to the /setting/setWanIeCfg endpoint with a malicious staticGw parameter. Example:

  POST /setting/setWanIeCfg HTTP/1.1
  Host: <router_ip>
  Content-Type: application/x-www-form-urlencoded
  
  staticGw=192.168.1.1; <malicious_command>
  

• Detection: Monitor network traffic for unusual patterns or requests to the /setting/setWanIeCfg endpoint. Implement intrusion detection systems (IDS) to detect and alert on suspicious activity.
• Response: In case of a detected exploitation attempt, isolate the affected device immediately and perform a thorough investigation to determine the extent of the compromise.

Conclusion

The command injection vulnerability in the TOTOLink A7100RU router firmware V7.4cu.2313_B20191024 is a critical issue that requires immediate attention. Organizations and individuals using this router should prioritize updating the firmware and implementing the recommended mitigation strategies to protect against potential attacks. The European cybersecurity community should be vigilant in monitoring for similar vulnerabilities in other network devices to maintain a robust security posture.