EUVD-2023-40323

Comprehensive Technical Analysis of EUVD-2023-40323

1. Vulnerability Assessment and Severity Evaluation

The vulnerability EUVD-2023-40323 affects the TP-Link TL-WR940N V4 wireless router. Specifically, it involves a buffer overflow in the ipStart parameter within the /userRpm/WanDynamicIpV6CfgRpm module. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted GET request.

Severity Evaluation:

• Base Score: 9.9 (Critical)
• Base Score Version: CVSS:3.1
• Base Score Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

The CVSS score of 9.9 indicates a critical vulnerability. The vector string highlights several key factors:

• Attack Vector (AV): Network (N) - The vulnerability is exploitable over the network.
• Attack Complexity (AC): Low (L) - The attack requires minimal skill and resources.
• Privileges Required (PR): Low (L) - The attacker needs low-level privileges to exploit the vulnerability.
• User Interaction (UI): None (N) - No user interaction is required for the attack to succeed.
• Scope (S): Changed (C) - The vulnerability affects a different security scope.
• Confidentiality (C), Integrity (I), Availability (A): High (H) - All three CIA triad components are highly impacted.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Network-Based Attack: An attacker can send a specially crafted GET request to the vulnerable router over the network.
• Remote Exploitation: Given the low attack complexity and the network attack vector, this vulnerability can be exploited remotely.

Exploitation Methods:

• Buffer Overflow: The attacker can send a GET request with a maliciously crafted ipStart parameter that exceeds the buffer size, leading to a buffer overflow.
• DoS Attack: The buffer overflow can cause the router to crash or become unresponsive, resulting in a Denial of Service.

3. Affected Systems and Software Versions

Affected Systems:

• TP-Link TL-WR940N V4 wireless router

Software Versions:

• The specific firmware versions affected are not explicitly mentioned in the entry, but it is implied that all versions of the firmware for the TL-WR940N V4 router are potentially vulnerable until patched.

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Firmware Update: Ensure that the router's firmware is updated to the latest version provided by TP-Link.
• Network Segmentation: Isolate the router from critical networks to limit the potential impact of an attack.
• Firewall Rules: Implement strict firewall rules to block unauthorized access to the router's management interface.

Long-Term Mitigation:

• Regular Patching: Establish a regular patching schedule to ensure all devices are updated with the latest security patches.
• Intrusion Detection Systems (IDS): Deploy IDS to monitor for suspicious network activity.
• Security Audits: Conduct regular security audits to identify and mitigate potential vulnerabilities.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to European organizations and individuals using the affected TP-Link router. Given the widespread use of such devices in both home and small business environments, the potential for widespread disruption is high. The critical nature of the vulnerability underscores the importance of timely patching and proactive security measures to protect against such threats.

6. Technical Details for Security Professionals

Vulnerability Details:

• Module: /userRpm/WanDynamicIpV6CfgRpm
• Parameter: ipStart
• Vulnerability Type: Buffer Overflow
• Exploitation: Crafted GET request leading to buffer overflow and DoS

References:

• GitHub Repository
• Packet Storm Security

Aliases:

• CVE-2023-36355
• GSD-2023-36355

Assigner:

• Mitre

EPSS Score:

• 5 (Indicates a moderate likelihood of exploitation)

ENISA IDs:

• Product: n/a
• Vendor: n/a

This comprehensive analysis highlights the critical nature of the vulnerability and the urgent need for mitigation strategies to protect against potential exploitation.