CVE-2025-67073

Comprehensive Technical Analysis of CVE-2025-67073

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2025-67073

Description: The vulnerability is a buffer overflow in the fromAdvSetMacMtuWan function of the httpd binary in Tenda AC10V4.0 V16.03.10.20. This flaw allows remote attackers to cause a denial of service (DoS) and potentially execute arbitrary code by sending a specially crafted POST request to the /goform/AdvSetMacMtuWan endpoint with a malicious serviceName field.

CVSS Score: 9.8

Severity Evaluation: A CVSS score of 9.8 indicates a critical vulnerability. The high score is due to the potential for remote code execution, which can lead to complete system compromise. The vulnerability's impact on confidentiality, integrity, and availability is severe, making it a high-priority issue for immediate remediation.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Remote Exploitation: Attackers can exploit this vulnerability over the network without requiring local access.
• Crafted Payload: The attack involves sending a POST request with a specially crafted serviceName field to the vulnerable endpoint.

Exploitation Methods:

• Buffer Overflow: By sending a payload that exceeds the buffer size allocated for the serviceName field, attackers can overwrite adjacent memory, leading to a crash or arbitrary code execution.
• Denial of Service (DoS): The buffer overflow can cause the httpd process to crash, resulting in a DoS condition.
• Code Execution: If the attacker can control the overwritten memory, they may inject and execute malicious code, leading to full system compromise.

3. Affected Systems and Software Versions

Affected Systems:

• Tenda AC10V4.0 routers running firmware version V16.03.10.20.

Software Versions:

• The vulnerability specifically affects the httpd binary in the mentioned firmware version.

4. Recommended Mitigation Strategies

Immediate Actions:

• Firmware Update: Apply the latest firmware update from Tenda as soon as it becomes available.
• Network Segmentation: Isolate the affected devices from critical networks to limit potential damage.
• Firewall Rules: Implement strict firewall rules to restrict access to the vulnerable endpoint.

Long-Term Strategies:

• Regular Patching: Ensure that all network devices are regularly updated with the latest security patches.
• Intrusion Detection Systems (IDS): Deploy IDS to monitor for suspicious network activity targeting the vulnerable endpoint.
• Security Audits: Conduct regular security audits and vulnerability assessments to identify and mitigate similar issues.

5. Impact on Cybersecurity Landscape

Broader Implications:

• Supply Chain Security: This vulnerability highlights the importance of securing IoT devices and network equipment, which are often overlooked in security strategies.
• Remote Exploitation: The ability to exploit this vulnerability remotely underscores the need for robust perimeter security and continuous monitoring.
• Firmware Security: Manufacturers must prioritize secure coding practices and regular security updates for firmware to mitigate such risks.

6. Technical Details for Security Professionals

Vulnerability Details:

• Function: fromAdvSetMacMtuWan
• Binary: httpd
• Endpoint: /goform/AdvSetMacMtuWan
• Payload Field: serviceName

Exploitation Steps:

1. Identify Target: Locate Tenda AC10V4.0 routers running the vulnerable firmware version.
2. Craft Payload: Create a POST request with a serviceName field that exceeds the buffer size.
3. Send Request: Use a tool like curl or a custom script to send the crafted POST request to the vulnerable endpoint.
4. Observe Impact: Monitor the target device for crashes or unusual behavior indicating successful exploitation.

Detection and Response:

• Log Analysis: Review logs for unusual POST requests to the /goform/AdvSetMacMtuWan endpoint.
• Memory Dumps: Analyze memory dumps of the httpd process to identify buffer overflow patterns.
• Incident Response: Follow incident response procedures to contain and remediate the vulnerability, including isolating affected devices and applying patches.

Conclusion

CVE-2025-67073 represents a critical security risk for Tenda AC10V4.0 routers running the specified firmware version. Immediate mitigation strategies, including firmware updates and network segmentation, are essential to protect against potential exploitation. The broader cybersecurity community should take this vulnerability as a reminder of the importance of securing IoT devices and maintaining robust perimeter defenses.