Overview
The digital ecosystem is constantly evolving, and with this evolution comes an ever-increasing need for tight security measures. A recent vulnerability, identified as CVE-2025-9088, has been found in the Tenda AC20 16.03.08.12. This vulnerability exposes users to a potential system compromise or data leakage. It affects the function save_virtualser_data of the file /goform/formSetVirtualSer, leading to a stack-based buffer overflow. This post seeks to delve into the details of this vulnerability, its potential impact, and ways to mitigate it.
The importance of understanding this vulnerability cannot be overstated. As it affects a common networking device, the Tenda AC20, it has the potential to impact thousands, if not millions, of users worldwide. It poses a significant threat to the integrity and confidentiality of data and systems connected to these devices.
Vulnerability Summary
CVE ID: CVE-2025-9088
Severity: Critical (8.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
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Product | Affected Versions
Tenda AC20 | 16.03.08.12
How the Exploit Works
The vulnerability stems from a lack of proper input validation in the function save_virtualser_data of the file /goform/formSetVirtualSer. An attacker can manipulate the argument list, causing a buffer overflow. A buffer overflow is a common coding error that can lead to arbitrary code execution. In this case, the attacker could execute malicious code remotely, leading to a potential system compromise or data leakage.
Conceptual Example Code
Here is a conceptual example of how the vulnerability might be exploited. This is not actual exploit code, but rather a simplified representation to illustrate the attack.
POST /goform/formSetVirtualSer HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "arguments": "A".repeat(1025) } // Exceeds the buffer sizeIn this example, the attacker sends a POST request with an overly long argument list, causing a buffer overflow in the save_virtualser_data function.
Mitigation
Users are advised to apply the vendor patch as soon as it becomes available. In the interim, users can use a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as a temporary mitigation measure. These tools can help to detect and block exploit attempts, reducing the risk of a successful attack.