Overview
The CVE-2025-10815 is a severe vulnerability discovered in the Tenda AC20 up to version 16.03.08.12. This flaw is found within the HTTP POST Request Handler, specifically the strcpy function of the file /goform/SetPptpServerCfg. The vulnerability is triggered by the manipulation of the argument startIp, leading to a buffer overflow. Buffer Overflow vulnerabilities are critical because they can allow an attacker to execute arbitrary code, potentially leading to complete system compromise. This vulnerability is especially concerning as an exploit is publicly available and can be launched remotely, posing a significant risk to any unpatched systems.
Vulnerability Summary
CVE ID: CVE-2025-10815
Severity: Critical (CVSS Score 8.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise and 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 AC20 | Up to version 16.03.08.12
How the Exploit Works
The exploit takes advantage of a buffer overflow vulnerability in the strcpy function of the file /goform/SetPptpServerCfg in Tenda AC20. By sending a specially crafted HTTP POST request with manipulated startIp argument, an attacker can overflow the buffer, causing undefined behavior in the system. This could potentially allow the attacker to execute arbitrary code, leading to a system compromise.
Conceptual Example Code
This is a conceptual example of how the vulnerability might be exploited. It is a sample HTTP POST request that an attacker could use to exploit the vulnerability.
POST /goform/SetPptpServerCfg HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
startIp=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA...In this example, the `startIp` parameter is filled with an excessive number of “A” characters, causing a buffer overflow.
Recommended Mitigations
Users of Tenda AC20 are strongly advised to apply the patch provided by the vendor. If the patch cannot be applied immediately, users can use a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) as a temporary mitigation. Regular monitoring for any unusual activity is also recommended until the patch can be applied.
