Overview
The Common Vulnerabilities and Exposures (CVE) system has identified a high-risk vulnerability, dubbed CVE-2025-9046, within Tenda AC20 version 16.03.08.12. This vulnerability exposes the home routers to risks of system compromise and data leakage. It primarily affects the function sub_46A2AC of the file /goform/setMacFilterCfg. Cybersecurity professionals and home users who utilize Tenda AC20 routers should take immediate notice of this issue due to the severity of the potential consequences. The exploit is publicly disclosed and could be leveraged by malicious actors.
Vulnerability Summary
CVE ID: CVE-2025-9046
Severity: High (8.8 CVSS Score)
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: System compromise and data leakage
Affected Products
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Product | Affected Versions
Tenda AC20 | 16.03.08.12
How the Exploit Works
The vulnerability lies in the manipulation of the ‘deviceList’ argument within the function sub_46A2AC of the file /goform/setMacFilterCfg. By sending specially crafted data, an attacker can trigger a stack-based buffer overflow. This overflow condition allows a remote attacker to overwrite the intended buffer boundaries, causing arbitrary code execution or altering the intended control flow of the program, thus potentially leading to system compromise or data leakage.
Conceptual Example Code
The following is a conceptual example of a malicious HTTP request that could be used to exploit the vulnerability:
POST /goform/setMacFilterCfg HTTP/1.1
Host: target.example.com
Content-Type: application/json
{
"deviceList": "AAAAA....[Long string of A's to cause buffer overflow]....AAAAA"
}In this example, a long string of ‘A’s is used in the ‘deviceList’ value to cause the buffer overflow. This is a common technique in buffer overflow exploits, although actual attack payloads would likely contain machine code to be executed on the victim’s system.
Please note that this is a simplified example and real-world exploitation might require a more sophisticated approach.
Mitigation
Users are strongly advised to apply the vendor patch as soon as it becomes available. In the meantime, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) could be used to mitigate this vulnerability. These systems can help detect and block malicious activity, providing temporary relief from the threat. Properly configured, they can prevent the exploit from reaching the vulnerable system, thus reducing the risk of a successful attack.