EUVD-2023-30850

Comprehensive Technical Analysis of EUVD-2023-30850

1. Vulnerability Assessment and Severity Evaluation

The vulnerability EUVD-2023-30850, also known as CVE-2023-27061, pertains to a buffer overflow issue in the Tenda V15V1.0 V15.11.0.14(1521_3190_1058) firmware. Specifically, the vulnerability resides in the wifiFilterListRemark parameter within the modifyWifiFilterRules function. This flaw allows attackers to execute a Denial of Service (DoS) attack through a specially crafted request.

Severity Evaluation:

• CVSS Base Score: 9.8
• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

The high base score of 9.8 indicates a critical vulnerability. The CVSS vector breakdown shows that the vulnerability can be exploited over the network (AV:N), requires low attack complexity (AC:L), does not need privileges (PR:N) or user interaction (UI:N), and has a high impact on confidentiality, integrity, and availability (C:H/I:H/A:H).

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Network-Based Attack: Given the CVSS vector (AV:N), the attack can be executed remotely over the network.
• Crafted Request: The attacker can send a specially crafted request to the vulnerable modifyWifiFilterRules function, exploiting the buffer overflow in the wifiFilterListRemark parameter.

Exploitation Methods:

• Buffer Overflow: By sending a request with an overly long wifiFilterListRemark parameter, the attacker can overflow the buffer, leading to a DoS condition.
• Code Execution: Although not explicitly mentioned, buffer overflows can sometimes be leveraged for arbitrary code execution, depending on the specific implementation and mitigations in place.

3. Affected Systems and Software Versions

Affected Systems:

• Tenda V15V1.0 devices running firmware version V15.11.0.14(1521_3190_1058).

Software Versions:

• Specifically, the vulnerability affects the firmware version V15.11.0.14(1521_3190_1058).

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Firmware Update: Ensure that all Tenda V15V1.0 devices are updated to the latest firmware version that addresses this vulnerability.
• Network Segmentation: Isolate vulnerable devices from critical networks to limit the potential impact of an attack.
• Firewall Rules: Implement strict firewall rules to restrict access to the vulnerable function from untrusted networks.

Long-Term Mitigation:

• Regular Patching: Establish a regular patching and update schedule for all IoT devices.
• 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 networked devices.

5. Impact on European Cybersecurity Landscape

The vulnerability in Tenda devices highlights the broader issue of IoT security within the European cybersecurity landscape. Given the widespread use of IoT devices in both consumer and industrial settings, such vulnerabilities can have far-reaching implications:

• Critical Infrastructure: IoT devices are increasingly integrated into critical infrastructure, making them attractive targets for cyber-attacks.
• Consumer Safety: Vulnerabilities in consumer IoT devices can lead to privacy breaches and potential physical harm.
• Regulatory Compliance: Organizations must ensure compliance with regulations such as GDPR and the upcoming NIS2 Directive, which emphasize the security of networked devices.

6. Technical Details for Security Professionals

Vulnerability Details:

• Function: modifyWifiFilterRules
• Parameter: wifiFilterListRemark
• Issue: Buffer overflow due to insufficient input validation.

Exploitation Steps:

1. Identify Target: Locate Tenda V15V1.0 devices running the vulnerable firmware.
2. Craft Request: Create a request with an overly long wifiFilterListRemark parameter.
3. Send Request: Transmit the crafted request to the target device, triggering the buffer overflow.

Detection and Response:

• Log Analysis: Monitor logs for unusual activity related to the modifyWifiFilterRules function.
• Anomaly Detection: Implement anomaly detection mechanisms to identify abnormal request patterns.
• Incident Response: Develop an incident response plan specific to IoT device vulnerabilities, including containment, eradication, and recovery steps.

References:

• GitHub Repository

By addressing this vulnerability promptly and implementing robust security measures, organizations can mitigate the risk posed by EUVD-2023-30850 and enhance their overall cybersecurity posture.