CVE-2025-7747 in FH451
Summary
by MITRE • 07/17/2025
A vulnerability classified as critical has been found in Tenda FH451 1.0.0.9. This affects the function fromWizardHandle of the file /goform/WizardHandle of the component POST Request Handler. The manipulation of the argument PPW leads to buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 07/19/2025
The vulnerability identified as CVE-2025-7747 represents a critical buffer overflow condition within the Tenda FH451 router firmware version 1.0.0.9. This flaw exists within the web-based management interface, specifically in the fromWizardHandle function located in the /goform/WizardHandle file. The vulnerability manifests during processing of POST requests to the affected component, where the PPW argument becomes susceptible to manipulation that can trigger memory corruption. The attack vector is remotely exploitable, meaning an unauthenticated attacker can potentially leverage this vulnerability without requiring physical access to the device or prior authentication credentials.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The POST Request Handler component serves as the entry point for this attack, suggesting that the application fails to properly validate or sanitize input parameters before processing them within memory buffers. The specific manipulation of the PPW argument indicates that the router's firmware does not implement adequate input validation mechanisms to prevent excessive data from being written to predetermined memory locations. This type of vulnerability creates opportunities for attackers to execute arbitrary code on the affected device, potentially leading to complete system compromise.
The operational impact of CVE-2025-7747 extends beyond simple denial of service conditions, as the remote exploitability combined with the critical classification suggests potential for full system takeover. An attacker could leverage this vulnerability to gain unauthorized access to the router's administrative functions, potentially enabling them to modify network configurations, redirect traffic, or establish persistent backdoors. The fact that this exploit has been disclosed to the public increases the risk profile significantly, as it removes the element of exploit scarcity that typically protects systems from immediate exploitation. Network administrators face the urgent challenge of identifying affected devices and implementing remediation measures before malicious actors can exploit this weakness.
Security mitigations for this vulnerability should prioritize immediate firmware updates from Tenda, as the vendor would need to address the buffer overflow condition through proper input validation and bounds checking mechanisms. Network segmentation and firewall rules can provide temporary protection by blocking access to the affected web interface from untrusted networks. The implementation of intrusion detection systems capable of identifying exploitation attempts targeting this specific vulnerability would also be beneficial. Organizations should conduct comprehensive inventory assessments to identify all affected Tenda FH451 devices within their network infrastructure and prioritize remediation efforts accordingly. This vulnerability demonstrates the importance of secure coding practices and proper input validation in network infrastructure devices, aligning with ATT&CK technique T1210 which covers exploitation of remote services and T1068 which involves the use of local privileges to escalate access. The public disclosure of the exploit means that defensive measures must be implemented urgently to protect against active exploitation attempts.