Overview
The critical vulnerability CVE-2025-7855, discovered in Tenda FH451 1.0.0.9, poses a significant threat to cybersecurity due to its potential for remote execution of arbitrary code. The vulnerability lies in the fromqossetting function of the /goform/qossetting file, and its exploitation could lead to severe consequences such as a full system compromise or data leakage. Given the ubiquity of Tenda devices in personal and professional environments, addressing this vulnerability should be a priority for all users and administrators.
Vulnerability Summary
CVE ID: CVE-2025-7855
Severity: Critical (8.8 CVSS Score)
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: System compromise and potential data leakage
Affected Products
Escape the Surveillance Era
Most apps won’t tell you the truth.
They’re part of the problem.
Phone numbers. Emails. Profiles. Logs.
It’s all fuel for surveillance.
Ameeba Chat gives you a way out.
- • No phone number
- • No email
- • No personal info
- • Anonymous aliases
- • End-to-end encrypted
Chat without a trace.
Product | Affected Versions
Tenda FH451 | 1.0.0.9
How the Exploit Works
The exploit works by manipulating the ‘page’ argument in the ‘fromqossetting’ function of the ‘/goform/qossetting’ file. This manipulation results in a stack-based buffer overflow, creating an opportunity for attackers to inject and execute arbitrary code. Since the attacker does not require any privileges and there’s no need for user interaction, the exploit can be launched remotely, significantly increasing its potential reach.
Conceptual Example Code
Here’s a conceptual example of how an HTTP request exploiting this vulnerability might look:
POST /goform/qossetting HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
page=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA...In the above example, ‘A’ represents a character string long enough to overflow the stack buffer.
Mitigation Guidance
The most effective mitigation strategy is to apply the vendor-supplied patch as soon as it is available. If for any reason, immediate patching is not possible, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as a temporary measure to block potential exploit attempts. Regularly updated signatures on these systems can help detect and prevent attacks exploiting this vulnerability.
Always remember, the best defense against cybersecurity threats is a proactive approach to security.