EUVD-2025-26203

Comprehensive Technical Analysis of EUVD-2025-26203

1. Vulnerability Assessment and Severity Evaluation

The vulnerability identified in EUVD-2025-26203 affects Tenda AC21 and AC23 routers, specifically in the firmware version 16.03.08.16. The issue resides in the GetParentControlInfo function within the file /goform/GetParentControlInfo, where a stack-based buffer overflow can occur due to manipulation of the mac argument. This vulnerability is severe, with a CVSS base score of 9.3, indicating a critical risk.

CVSS Vector Breakdown:

• AV:N (Attack Vector: Network) - The vulnerability can be exploited remotely over the network.
• AC:L (Attack Complexity: Low) - The attack requires low complexity to exploit.
• AT:N (Attack Type: None) - No specific attack type is required.
• PR:N (Privileges Required: None) - No privileges are required to exploit the vulnerability.
• UI:N (User Interaction: None) - No user interaction is required.
• VC:H (Vulnerability Consequence: High) - The impact on confidentiality is high.
• VI:H (Vulnerability Impact: High) - The impact on integrity is high.
• VA:H (Vulnerability Availability: High) - The impact on availability is high.
• SC:N (Scope Change: None) - The scope does not change.
• SI:N (Scope Impact: None) - The impact on the scope is none.
• SA:N (Scope Availability: None) - The availability impact on the scope is none.
• E:P (Exploit Code Maturity: Proof-of-Concept) - Proof-of-concept exploit code is available.

2. Potential Attack Vectors and Exploitation Methods

Given the nature of the vulnerability, potential attack vectors include:

• Remote Exploitation: An attacker can remotely exploit the vulnerability by sending crafted network packets to the affected router.
• Buffer Overflow: The attacker can manipulate the mac argument to cause a stack-based buffer overflow, leading to arbitrary code execution.
• Public Exploit Availability: The exploit has been disclosed publicly, increasing the likelihood of widespread attacks.

3. Affected Systems and Software Versions

The affected systems are:

• Tenda AC21 Router with firmware version 16.03.08.16.
• Tenda AC23 Router with firmware version 16.03.08.16.

4. Recommended Mitigation Strategies

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

• Firmware Update: Immediately update the firmware of the affected routers to a patched version provided by Tenda.
• Network Segmentation: Implement network segmentation to isolate critical systems and reduce the attack surface.
• Firewall Rules: Configure firewall rules to restrict access to the router's management interface.
• Intrusion Detection Systems (IDS): Deploy IDS to monitor for suspicious network activity and potential exploitation attempts.
• Regular Audits: Conduct regular security audits and vulnerability assessments to identify and address potential security issues.

5. Impact on European Cybersecurity Landscape

The disclosure of this vulnerability has significant implications for the European cybersecurity landscape:

• Widespread Deployment: Tenda routers are widely deployed in both residential and small business environments, increasing the potential impact.
• Critical Infrastructure: Routers are critical components of network infrastructure, and their compromise can lead to broader network breaches.
• Regulatory Compliance: Organizations must ensure compliance with relevant regulations, such as GDPR, by addressing vulnerabilities promptly.

6. Technical Details for Security Professionals

Vulnerability Details:

• Function: GetParentControlInfo
• File: /goform/GetParentControlInfo
• Argument: mac
• Issue: Stack-based buffer overflow

Exploitation Steps:

1. Identify Target: Identify the target router with the vulnerable firmware version.
2. Craft Payload: Craft a malicious payload that manipulates the mac argument to cause a buffer overflow.
3. Send Payload: Send the crafted payload to the router's management interface.
4. Execute Code: If successful, the payload will execute arbitrary code on the router.

References:

• VulDB Entry
• CTI Entry
• GitHub Repository
• GitHub Repository
• Tenda Official Website

Aliases:

• CVE-2025-9605

Assigner:

• VulDB

ENISA ID Product:

• AC23: Version 16.03.08.16
• AC21: Version 16.03.08.16

ENISA ID Vendor:

• Tenda

By addressing this vulnerability promptly and effectively, organizations can mitigate the risk of potential cyber-attacks and ensure the security and integrity of their network infrastructure.