Overview
This blog post provides an in-depth analysis of the critical vulnerability CVE-2025-9023, that affects Tenda AC7 and AC18 routers of specified versions. This vulnerability, linked to a buffer overflow issue, poses significant risks to personal and organizational data and network security. It primarily resides in the function formSetSchedLed of the file /goform/SetLEDCfg, with the manipulation of the ‘Time’ argument leading to this buffer overflow vulnerability.
The exploit can be launched remotely, making it particularly dangerous as it does not require physical access to the targeted device. It is crucial to understand this vulnerability, its potential impacts, and possible mitigation measures, especially considering that the exploit has been disclosed to the public.
Vulnerability Summary
CVE ID: CVE-2025-9023
Severity: High (8.8 CVSS Severity Score)
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 AC7 | 15.03.05.19
Tenda AC18 | 15.03.06.44
How the Exploit Works
The exploit works by manipulating the ‘Time’ argument in the ‘formSetSchedLed’ function of the ‘/goform/SetLEDCfg’ file. This manipulation leads to a buffer overflow vulnerability. Buffer overflow occurs when more data is written to a buffer than it can handle, leading to the overwriting of adjacent memory spaces. In this case, the overflow can be exploited to execute arbitrary code or cause a denial of service, potentially leading to system compromise or data leakage.
Conceptual Example Code
Here’s a conceptual example illustrating how an attacker might exploit this vulnerability. This example uses a malicious HTTP POST request to manipulate the ‘Time’ argument:
POST /goform/SetLEDCfg HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "Time": "buffer_overflow_generating_input" }In this example, the “buffer_overflow_generating_input” is a placeholder for the actual malicious payload that would cause buffer overflow.
Mitigation Guidance
Users of affected Tenda AC7 and AC18 versions are strongly advised to apply patches provided by the vendor as soon as possible. In cases where immediate patching is not feasible, implementing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure. These tools can help detect and block exploit attempts, providing an additional layer of protection against this vulnerability.