EUVD-2023-30811

Comprehensive Technical Analysis of EUVD-2023-30811

1. Vulnerability Assessment and Severity Evaluation

The vulnerability EUVD-2023-30811, also known as CVE-2023-27021, pertains to a stack overflow in the formSetFirewallCfg function within the Tenda AC10 router firmware version US_AC10V4.0si_V16.03.10.13_cn. This vulnerability is critical, with a CVSS base score of 9.8, indicating a high risk to affected systems. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H highlights the following characteristics:

• Attack Vector (AV): Network (N) - The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low (L) - Exploiting the vulnerability 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 for the exploit to succeed.
• Scope (S): Unchanged (U) - The vulnerability does not affect other systems beyond the targeted device.
• Confidentiality (C): High (H) - The vulnerability can lead to a significant breach of confidentiality.
• Integrity (I): High (H) - The vulnerability can compromise the integrity of the system.
• Availability (A): High (H) - The vulnerability can cause a complete loss of availability.

2. Potential Attack Vectors and Exploitation Methods

The stack overflow vulnerability in the formSetFirewallCfg function can be exploited through crafted payloads sent to the router. Potential attack vectors include:

• Remote Exploitation: An attacker can send specially crafted packets to the router over the network, leading to a stack overflow.
• Denial of Service (DoS): By exploiting the vulnerability, an attacker can cause the router to crash, resulting in a DoS condition.
• Arbitrary Code Execution: The stack overflow can be leveraged to execute arbitrary code on the router, potentially allowing the attacker to gain control over the device.

3. Affected Systems and Software Versions

The vulnerability specifically affects the Tenda AC10 router with the firmware version US_AC10V4.0si_V16.03.10.13_cn. Other versions of the Tenda AC10 router firmware may also be affected, but this has not been confirmed. Users and administrators should verify the firmware version of their Tenda AC10 routers to determine if they are at risk.

4. Recommended Mitigation Strategies

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

• Firmware Update: Immediately update the router firmware to a version that addresses this vulnerability. Tenda should be contacted for the latest firmware updates.
• Network Segmentation: Implement network segmentation to isolate the router from critical systems, reducing the potential impact of an exploit.
• Firewall Configuration: Configure firewalls to restrict access to the router, allowing only trusted IP addresses to communicate with it.
• Intrusion Detection Systems (IDS): Deploy IDS to monitor network traffic for suspicious activity that may indicate an attempt to exploit this vulnerability.
• Regular Audits: Conduct regular security audits and vulnerability assessments to identify and address potential security weaknesses.

5. Impact on European Cybersecurity Landscape

The vulnerability in the Tenda AC10 router poses a significant risk to European cybersecurity, particularly for organizations and individuals relying on this device for network connectivity. The potential for remote exploitation and arbitrary code execution makes it a high-priority issue for cybersecurity professionals. The widespread use of routers in both residential and commercial settings amplifies the risk, as compromised routers can serve as entry points for further attacks on connected systems.

6. Technical Details for Security Professionals

For security professionals, the following technical details are pertinent:

• Vulnerability Type: Stack Overflow
• Affected Function: formSetFirewallCfg
• Exploit Method: Crafted payloads sent to the router can trigger the stack overflow.
• Impact: DoS, arbitrary code execution, potential loss of confidentiality, integrity, and availability.
• Mitigation: Update firmware, implement network segmentation, configure firewalls, deploy IDS, and conduct regular security audits.

References:

• GitHub Repository

By addressing this vulnerability promptly and implementing robust mitigation strategies, organizations can significantly reduce the risk of exploitation and protect their network infrastructure.