Overview
This post brings to light a highly critical vulnerability found in the Tenda FH451 1.0.0.9 router. Identified as CVE-2025-7807, this security flaw poses a significant risk to all users of the affected router. An attacker can exploit this vulnerability remotely to trigger a stack-based buffer overflow that can potentially compromise the entire system or lead to data leakage.
Considering the severity of the impact and the fact that the vulnerability details are now public, it is absolutely crucial for users and administrators to take immediate steps to mitigate this risk. A failure to do so could result in severe consequences, including unauthorized system access, data breaches, and potential disruption of network services.
Vulnerability Summary
CVE ID: CVE-2025-7807
Severity: Critical, with a CVSS score of 8.8
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: Potential system compromise and data leakage
Affected Products
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Product | Affected Versions
Tenda FH451 | 1.0.0.9
How the Exploit Works
The vulnerability resides in the fromSafeUrlFilter function of the /goform/SafeUrlFilter file in the Tenda FH451 1.0.0.9 router. The improper handling of the Go/page argument within this function can lead to a stack-based buffer overflow.
A buffer overflow occurs when more data is put into a buffer than it can handle, causing the extra data to overflow into adjacent memory locations. In this case, an attacker can craft and send a specially formatted request to the vulnerable function, causing a buffer overflow. This can allow the execution of arbitrary code, leading to potential system compromise or data leakage.
Conceptual Example Code
The following conceptual code illustrates how an attacker might exploit this vulnerability. Note that this is a simplified example and real-world exploits might be more complex and difficult to detect.
POST /goform/SafeUrlFilter HTTP/1.1
Host: target_router_ip
Content-Type: application/x-www-form-urlencoded
Go/page=[MALICIOUS_PAYLOAD]In the above example, [MALICIOUS_PAYLOAD] would be replaced with a specially crafted string that causes a buffer overflow in the SafeUrlFilter function.
Mitigation
Users and administrators are advised to apply the vendor patch as soon as it is available. In the meantime, utilizing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. These tools can help detect and block attempts to exploit this vulnerability. However, they are not a permanent solution and should be used in conjunction with other security measures, such as patch management and regular software updates.