Overview
CVE-2025-5609 is a critical vulnerability found in Tenda AC18 15.03.05.05, a widely-used networking device. This vulnerability, affecting the function fromadvsetlanip in the file /goform/AdvSetLanip, has been publicly disclosed and is known to be exploitable. Given the severity of the issue and the potential for system compromise or data leakage, it’s crucial for users and administrators of Tenda AC18 devices to understand the risks, apply mitigation strategies, and stay informed about any further developments.
Vulnerability Summary
CVE ID: CVE-2025-5609
Severity: Critical (CVSS: 8.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise and potential data leakage
Affected Products
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Product | Affected Versions
Tenda | AC18 15.03.05.05
How the Exploit Works
The vulnerability lies in the handling of the ‘lanMask’ argument in the fromadvsetlanip function. By manipulating this argument, an attacker can trigger a buffer overflow condition. This condition can lead to unexpected behavior, including system crashes, data corruption, and in worst-case scenarios, allow the attacker to execute arbitrary code or control the system.
Conceptual Example Code
The actual exploit code is not provided to prevent misuse, but a conceptual example can help understand how an attack might be carried out. In a hypothetical attack, a malicious actor might send an HTTP POST request with an oversized ‘lanMask’ argument to the vulnerable endpoint.
POST /goform/AdvSetLanip HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
lanMask=256.256.256.256&...[remainder of the payload]In this example, ‘lanMask’ is set to a value that exceeds the expected input size, potentially triggering a buffer overflow. This could lead to memory corruption, crashing the system, or potentially allowing the attacker to execute arbitrary code.
Mitigation
Tenda users are advised to apply patches provided by the vendor as soon as possible. If patches are not immediately available or if patching is not immediately feasible, temporary mitigation can be achieved by implementing a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) to detect and block exploit attempts. As a best practice, regular software updates should be a part of routine system maintenance to avoid falling victim to known vulnerabilities.