CVE-2023-47455

Comprehensive Technical Analysis of CVE-2023-47455

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2023-47455 CISA Vulnerability Name: CVE-2023-47455 CVSS Score: 9.1

The vulnerability in question is a heap overflow in the setSchedWifi function of Tenda AX1806 V1.0.0.1. This vulnerability arises because the function does not properly validate the size of the schedStartTime and schedEndTime parameters obtained from HTTP requests. This lack of validation can lead to a heap overflow, which is a critical issue as it can result in arbitrary code execution, denial of service, or other unintended behaviors.

Severity Evaluation:

• CVSS Score: 9.1 (Critical)
• Impact: High
• Exploitability: High

The high CVSS score indicates that this vulnerability is severe and poses a significant risk to affected systems. The potential for remote code execution and denial of service makes it a high-priority issue for immediate remediation.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Remote Exploitation: An attacker can send specially crafted HTTP requests to the vulnerable device, exploiting the heap overflow to execute arbitrary code or cause a denial of service.
• Network-Based Attacks: Given that the vulnerability is in a function handling HTTP requests, it can be exploited over the network, making it accessible to remote attackers.

Exploitation Methods:

• Buffer Overflow: By sending oversized schedStartTime and schedEndTime parameters, an attacker can overflow the heap, leading to code execution or crashing the device.
• Payload Injection: An attacker can inject malicious payloads into the HTTP request parameters to achieve remote code execution.

3. Affected Systems and Software Versions

Affected Systems:

• Tenda AX1806 routers running firmware version V1.0.0.1.

Software Versions:

• Tenda AX1806 V1.0.0.1

It is crucial to note that other versions of the firmware may also be affected if they share the same codebase without proper validation mechanisms.

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Firmware Update: Apply the latest firmware update provided by Tenda that addresses this vulnerability.
• Network Segmentation: Isolate the affected devices from critical networks to limit the potential impact of an exploit.
• Firewall Rules: Implement strict firewall rules to restrict access to the device's management interface.

Long-Term Mitigation:

• Regular Patching: Ensure that all IoT devices are regularly updated with the latest security patches.
• Input Validation: Implement robust input validation mechanisms to prevent similar vulnerabilities in future firmware versions.
• Security Audits: Conduct regular security audits and vulnerability assessments on IoT devices.

5. Impact on Cybersecurity Landscape

The discovery of this vulnerability highlights the ongoing challenges in securing IoT devices. The potential for remote code execution and denial of service underscores the need for rigorous security practices in IoT device development and deployment. This vulnerability can be exploited to compromise home and small business networks, leading to data breaches, unauthorized access, and other malicious activities.

6. Technical Details for Security Professionals

Vulnerability Details:

• Function: setSchedWifi
• Parameters: schedStartTime, schedEndTime
• Issue: Lack of size validation for src and v12 parameters obtained from HTTP requests.

Exploitation Steps:

1. Identify Target: Locate a Tenda AX1806 router running the vulnerable firmware version.
2. Craft Payload: Create an HTTP request with oversized schedStartTime and schedEndTime parameters.
3. Send Request: Send the crafted HTTP request to the target device.
4. Exploit: Achieve remote code execution or cause a denial of service.

Detection and Monitoring:

• Network Monitoring: Monitor network traffic for unusual HTTP requests targeting the setSchedWifi function.
• Log Analysis: Analyze device logs for signs of unexpected behavior or crashes.
• Intrusion Detection: Implement intrusion detection systems (IDS) to detect and alert on suspicious activities.

Conclusion: CVE-2023-47455 is a critical vulnerability that requires immediate attention from cybersecurity professionals. By understanding the technical details and implementing the recommended mitigation strategies, organizations can protect their networks and devices from potential exploitation. Regular updates, robust input validation, and continuous monitoring are essential for maintaining a secure cybersecurity posture.