EUVD-2024-39855

Comprehensive Technical Analysis of EUVD-2024-39855

1. Vulnerability Assessment and Severity Evaluation

The vulnerability described in EUVD-2024-39855 pertains to a command injection flaw in the handler function within the /goform/telnet endpoint of Tenda FH1206 v02.03.01.35. This vulnerability allows attackers to execute arbitrary commands via a crafted HTTP request. The CVSS (Common Vulnerability Scoring System) base score of 9.8 indicates a critical severity level. The scoring 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 is exploitable 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.
• Scope (S): Unchanged (U) - The vulnerability does not affect other systems beyond the initial target.
• Confidentiality (C): High (H) - Complete loss of confidentiality.
• Integrity (I): High (H) - Complete loss of integrity.
• Availability (A): High (H) - Complete loss of availability.

2. Potential Attack Vectors and Exploitation Methods

Attackers can exploit this vulnerability by crafting malicious HTTP requests targeting the /goform/telnet endpoint. The following steps outline a potential attack vector:

1. Reconnaissance: Identify the target device running Tenda FH1206 v02.03.01.35.
2. Crafting the Payload: Create an HTTP request that includes a specially crafted payload designed to inject arbitrary commands.
3. Execution: Send the crafted HTTP request to the vulnerable endpoint.
4. Command Execution: The handler function processes the request, leading to the execution of the injected commands with the privileges of the web server.

3. Affected Systems and Software Versions

The vulnerability specifically affects Tenda FH1206 devices running firmware version v02.03.01.35. It is crucial to note that other versions of the firmware or similar devices from Tenda might also be affected if they share the same codebase or handler function.

4. Recommended Mitigation Strategies

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

1. Firmware Update: Immediately update the firmware to a patched version if available. Regularly check for updates from the vendor.
2. Network Segmentation: Isolate IoT devices like the Tenda FH1206 from critical networks to limit the potential impact of an attack.
3. Firewall Rules: Implement strict firewall rules to restrict access to the /goform/telnet endpoint.
4. Intrusion Detection Systems (IDS): Deploy IDS to monitor for suspicious network activity targeting the vulnerable endpoint.
5. Access Controls: Enforce strong authentication and access controls to limit who can access the device.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to European organizations and individuals using the affected Tenda FH1206 devices. Given the critical nature of the vulnerability, successful exploitation could lead to:

• Data Breaches: Unauthorized access to sensitive information.
• Service Disruption: Compromise of device functionality, leading to service outages.
• Unauthorized Access: Attackers gaining control over the device and potentially pivoting to other systems within the network.

6. Technical Details for Security Professionals

For security professionals, the following technical details are pertinent:

• Exploit Code: The vulnerability can be exploited using a simple HTTP request with a crafted payload. Example:

  POST /goform/telnet HTTP/1.1
  Host: <target_ip>
  Content-Type: application/x-www-form-urlencoded
  
  cmd=<injected_command>
  

• Detection: Monitor network traffic for unusual HTTP requests targeting the /goform/telnet endpoint. Look for patterns indicative of command injection attempts.
• Response: In the event of an attack, isolate the affected device, capture logs for forensic analysis, and apply the necessary patches or updates.

Conclusion

EUVD-2024-39855 represents a critical vulnerability in Tenda FH1206 devices that requires immediate attention. Organizations should prioritize updating their firmware and implementing robust security measures to mitigate the risk. The European cybersecurity landscape must remain vigilant against such vulnerabilities to protect against potential data breaches and service disruptions.