CVE-2025-7855 in FH451
Summary
by MITRE • 07/20/2025
A vulnerability classified as critical was found in Tenda FH451 1.0.0.9. Affected by this vulnerability is the function fromqossetting of the file /goform/qossetting. The manipulation of the argument page leads to stack-based buffer overflow. The attack can be launched remotely.
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Analysis
by VulDB Data Team • 07/24/2025
The vulnerability identified as CVE-2025-7855 represents a critical stack-based buffer overflow flaw within the Tenda FH451 router firmware version 1.0.0.9. This vulnerability specifically affects the qossetting function located in the /goform/qossetting file, which is part of the router's web-based management interface. The flaw manifests when processing the page argument parameter, creating an exploitable condition that allows remote attackers to execute arbitrary code on the affected device. The issue stems from inadequate input validation and bounds checking within the firmware's handling of web form submissions, making it particularly dangerous as it can be exploited without requiring physical access or authentication credentials.
The technical nature of this vulnerability places it under CWE-121 Stack-based Buffer Overflow, which is classified as a fundamental memory corruption issue that occurs when more data is written to a fixed-length buffer than it can accommodate. This particular implementation flaw allows attackers to overwrite adjacent memory locations on the stack, potentially leading to arbitrary code execution, privilege escalation, or complete system compromise. The remote exploitability aspect means that attackers can leverage this vulnerability from outside the local network, making it particularly dangerous for home and small office network environments where routers are often exposed to the internet. The attack vector specifically targets the web management interface through HTTP requests that manipulate the page parameter, which then flows into vulnerable buffer operations without proper sanitization.
The operational impact of CVE-2025-7855 extends beyond simple remote code execution to encompass complete network compromise and potential data exfiltration capabilities. Successful exploitation could enable attackers to gain full administrative control over the router, allowing them to modify network settings, redirect traffic, establish persistent backdoors, or use the device as a pivot point for attacking other systems within the local network. This vulnerability directly aligns with ATT&CK technique T1021.001 Remote Services: Remote Desktop Protocol, as it provides unauthorized remote access to network infrastructure through the web interface. Additionally, it supports T1059 Command and Scripting Interpreter techniques by enabling arbitrary command execution, and T1566 Impersonation through the ability to manipulate network traffic and potentially intercept communications. The affected Tenda FH451 device represents a common target in botnet campaigns due to its widespread deployment and the typical lack of security updates from end users.
Mitigation strategies for CVE-2025-7855 must prioritize immediate firmware updates from Tenda's official sources, as this vulnerability is likely to be patched through vendor-supplied security updates. Network administrators should implement network segmentation and firewall rules to restrict access to the router's management interface, particularly limiting access to trusted internal networks only. The implementation of intrusion detection systems that monitor for suspicious web form submissions and unusual traffic patterns can help detect exploitation attempts. Regular security audits of network infrastructure should include verification of firmware versions and patch management processes. Organizations should also consider disabling unnecessary web management interfaces and implementing strong authentication mechanisms including multi-factor authentication where possible. The vulnerability's classification as critical underscores the importance of immediate remediation, as the combination of remote exploitability and stack-based buffer overflow creates a high-risk scenario that can lead to complete network compromise within minutes of exploitation.