CVE-2024-40416

Comprehensive Technical Analysis of CVE-2024-40416

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2024-40416 CVSS Score: 9.8

The vulnerability in question is a stack-based buffer overflow in the /goform/SetVirtualServerCfg function within the sub_6320C function of the Tenda AX1806 1.0.0.1 firmware. A CVSS score of 9.8 indicates a critical severity level, suggesting that this vulnerability poses a significant risk to affected systems.

Severity Evaluation:

• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

The high scores across all impact metrics indicate that successful exploitation could lead to unauthorized access, data corruption, and system downtime.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Network-Based Attack: An attacker could exploit this vulnerability over the network by sending specially crafted requests to the /goform/SetVirtualServerCfg endpoint.
• Local Exploitation: If an attacker has local access to the device, they could manipulate the input to the vulnerable function directly.

Exploitation Methods:

• Buffer Overflow: By sending a payload that exceeds the allocated buffer size, an attacker can overwrite adjacent memory, potentially leading to arbitrary code execution.
• Remote Code Execution (RCE): If the overflow allows for code injection, an attacker could execute malicious code on the device.

3. Affected Systems and Software Versions

Affected Systems:

• Tenda AX1806 routers running firmware version 1.0.0.1.

Software Versions:

• Tenda AX1806 firmware version 1.0.0.1.

It is crucial to note that other versions of the firmware may also be affected if they share the same vulnerable codebase.

4. Recommended Mitigation Strategies

Immediate Actions:

• Firmware Update: Apply the latest firmware update provided by Tenda, which should include a patch for this vulnerability.
• Network Segmentation: Isolate the affected devices on a separate network segment to limit potential attack vectors.
• Access Control: Implement strict access controls to limit who can access and configure the device.

Long-Term Strategies:

• Regular Patching: Establish a regular patching schedule to ensure all devices are running the latest firmware.
• Intrusion Detection Systems (IDS): Deploy IDS to monitor for suspicious activity that may indicate an exploitation attempt.
• Security Audits: Conduct regular security audits to identify and mitigate potential vulnerabilities.

5. Impact on Cybersecurity Landscape

The discovery of this vulnerability highlights the ongoing risks associated with IoT devices, particularly routers, which are often targeted due to their critical role in network infrastructure. The high CVSS score underscores the need for robust security measures in IoT device management.

Broader Implications:

• Supply Chain Security: Vendors must prioritize secure coding practices and regular security audits.
• Consumer Awareness: Increased awareness among consumers about the importance of keeping firmware up to date.
• Regulatory Compliance: Potential for stricter regulations and standards for IoT device security.

6. Technical Details for Security Professionals

Vulnerability Details:

• Function: /goform/SetVirtualServerCfg
• Affected Code: sub_6320C
• Type: Stack-based buffer overflow

Exploitation Steps:

1. Identify the Target: Locate the Tenda AX1806 router on the network.
2. Craft the Payload: Develop a payload that exceeds the buffer size allocated for the SetVirtualServerCfg function.
3. Send the Request: Use a tool like curl or a custom script to send the malicious request to the vulnerable endpoint.
4. Execute Code: If successful, the overflow will allow for arbitrary code execution.

Detection and Prevention:

• Monitoring: Use network monitoring tools to detect unusual traffic patterns to the /goform/SetVirtualServerCfg endpoint.
• Input Validation: Ensure that all input to the SetVirtualServerCfg function is properly validated and sanitized.
• Code Review: Conduct thorough code reviews to identify and mitigate similar vulnerabilities in other functions.

References:

• GitHub Repository (Note: Links are currently broken)

By addressing this vulnerability promptly and implementing robust security measures, organizations can significantly reduce the risk of exploitation and maintain the integrity of their network infrastructure.