EUVD-2023-37827

Comprehensive Technical Analysis of EUVD-2023-37827

1. Vulnerability Assessment and Severity Evaluation

Vulnerability Description: The EUVD entry EUVD-2023-37827 describes a stack overflow vulnerability in the Tenda AC8V4.0-V16.03.34.06 firmware. This vulnerability is triggered via the deviceId parameter in the saveParentControlInfo function.

Severity Evaluation: The vulnerability has a CVSS Base Score of 9.8, which is considered critical. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H indicates the following:

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)

This high score underscores the critical nature of the vulnerability, indicating that it can be exploited remotely with low complexity, requiring no privileges or user interaction, and can result in high impacts on confidentiality, integrity, and availability.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Remote Exploitation: Given the network attack vector, an attacker can exploit this vulnerability over the network without needing physical access to the device.
• Malicious Input: The attacker can send specially crafted input to the deviceId parameter, causing a stack overflow.

Exploitation Methods:

• Buffer Overflow: By sending a large or malformed deviceId parameter, an attacker can overwrite adjacent memory, potentially leading to arbitrary code execution.
• Denial of Service (DoS): The stack overflow can cause the device to crash, resulting in a denial of service.

3. Affected Systems and Software Versions

Affected Systems:

• Tenda AC8V4.0 devices running firmware version V16.03.34.06.

Software Versions:

• Specifically, the vulnerability affects the saveParentControlInfo function within the firmware.

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Firmware Update: Users should immediately update to a patched version of the firmware if available.
• Network Segmentation: Isolate affected devices on a separate network segment to limit exposure.
• Firewall Rules: Implement strict firewall rules to restrict access to the device from untrusted networks.

Long-Term Mitigation:

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

5. Impact on European Cybersecurity Landscape

Impact Analysis:

• Widespread Deployment: Tenda devices are widely used in both residential and small business environments. This vulnerability could lead to widespread exploitation if not addressed promptly.
• Critical Infrastructure: If these devices are used in critical infrastructure, the impact could be severe, affecting the availability and integrity of essential services.
• Regulatory Compliance: Organizations must ensure compliance with EU regulations such as GDPR and NIS Directive, which mandate robust cybersecurity measures.

6. Technical Details for Security Professionals

Vulnerability Details:

• Function Affected: saveParentControlInfo
• Parameter: deviceId
• Vulnerability Type: Stack Overflow
• Exploitation: The vulnerability can be exploited by sending a specially crafted deviceId parameter that exceeds the buffer size, leading to memory corruption.

Detection and Response:

• Log Analysis: Monitor logs for unusual activity related to the saveParentControlInfo function.
• Incident Response: Have an incident response plan in place to quickly address any detected exploitation attempts.
• Threat Intelligence: Leverage threat intelligence feeds to stay informed about any active exploitation of this vulnerability.

References:

• GitHub Repository
• GitHub Tree

Conclusion: The stack overflow vulnerability in Tenda AC8V4.0-V16.03.34.06 firmware is critical and requires immediate attention. Organizations should prioritize updating affected devices and implementing robust security measures to mitigate the risk of exploitation. Continuous monitoring and regular security assessments are essential to maintain a strong cybersecurity posture.