CVE-2025-7794 in FH451
Summary
by MITRE • 07/18/2025
A vulnerability classified as critical was found in Tenda FH451 1.0.0.9. Affected by this vulnerability is the function fromNatStaticSetting of the file /goform/NatStaticSetting. The manipulation of the argument page leads to stack-based buffer overflow. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 07/23/2025
The vulnerability identified as CVE-2025-7794 represents a critical stack-based buffer overflow flaw within the Tenda FH451 router firmware version 1.0.0.9. This vulnerability specifically affects the fromNatStaticSetting function located in the /goform/NatStaticSetting file, which serves as a critical component in the router's network address translation configuration management system. The flaw manifests when the page argument is manipulated, allowing attackers to overflow the stack buffer and potentially execute arbitrary code on the affected device. The vulnerability's classification as critical stems from its remote exploitability and the fact that a public exploit has already been disclosed, making it immediately actionable by threat actors. This particular implementation flaw demonstrates a classic lack of proper input validation and bounds checking within the router's web interface form processing functionality.
The technical exploitation of this vulnerability occurs through a stack-based buffer overflow attack that leverages the improper handling of user-supplied input in the page parameter of the NatStaticSetting form. When an attacker sends a malformed request containing an excessively long page argument to the vulnerable router, the buffer overflow occurs in the stack memory region, potentially overwriting adjacent memory locations including return addresses and function pointers. This type of vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is categorized as a fundamental memory safety issue in software development. The attack vector is particularly dangerous because it can be executed remotely without requiring physical access to the device, making it a significant threat to network security infrastructure. The exploitation process typically involves crafting a malicious HTTP request that triggers the buffer overflow condition, potentially leading to complete system compromise and unauthorized access to the router's administrative functions.
The operational impact of CVE-2025-7794 extends beyond simple denial of service to encompass full system compromise and potential network infiltration capabilities. Once successfully exploited, attackers can gain administrative privileges on the affected router, allowing them to modify network configurations, redirect traffic, install malicious firmware, or establish persistent backdoors within the network infrastructure. This vulnerability particularly affects home and small office networks where routers often serve as the primary gateway and security boundary, making the compromise of such devices a significant threat to overall network security posture. The remote exploitability means that attackers can target these devices from anywhere on the internet, potentially leading to widespread compromise of networks that rely on Tenda FH451 routers. The vulnerability's impact is amplified by the fact that many users may not be aware of firmware updates or may delay applying security patches, creating a large attack surface for threat actors.
Mitigation strategies for CVE-2025-7794 should prioritize immediate firmware updates from Tenda, as this represents the most effective solution to address the underlying buffer overflow vulnerability. Network administrators should implement network segmentation and access control measures to limit the potential impact of exploitation, including restricting remote administrative access to the affected devices and implementing firewall rules to block unauthorized traffic to the router's management interfaces. Additional protective measures include monitoring network traffic for suspicious activity related to the affected form endpoint and implementing intrusion detection systems that can identify exploitation attempts targeting this specific vulnerability. Organizations should also consider implementing network access controls that prevent the router from directly accessing sensitive network resources, reducing the potential damage from successful exploitation. The vulnerability highlights the importance of proper input validation and memory safety practices in embedded systems development, aligning with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1566.001 for Phishing for Information, as attackers may leverage such vulnerabilities to establish persistent access and gather additional intelligence from compromised networks. Regular security assessments and vulnerability scanning should be implemented to identify similar flaws in other network infrastructure components, particularly in embedded systems where security updates may be infrequent or unavailable.