A recently discovered critical vulnerability (CVE-2025-3266) in qinguoyi TinyWebServer up to version 1. has raised serious concerns regarding the security of the software. This vulnerability, classified as critical, affects an unknown functionality of the file /http/http_conn.cpp in the server. By exploiting this stack-based buffer overflow vulnerability, a remote attacker could gain unauthorized access to the server, potentially leading to remote code execution and compromising the entire system.

Exploit Details

The vulnerability is caused by improper handling of specially crafted 'name' and 'password' arguments in the http_conn.cpp file, which leads to a stack-based buffer overflow. An attacker can remotely manipulate these arguments to overflow the buffer and execute arbitrary code on the victim's machine.

The following code snippet from the http_conn.cpp file demonstrates the vulnerable functionality

void http_conn::parse_name_password() {
    char name[MAX_LEN], password[MAX_LEN];
    strcpy(name, http_request->get_header_value("name"));
    strcpy(password, http_request->get_header_value("password"));
}

In this code snippet, the name and password variables are declared with a fixed buffer length of MAX_LEN, which in this case might not be enough for the values received from the user. When these values are copied using the strcpy function, it can potentially lead to a buffer overflow if the received values from the user are larger than the expected buffer length.

Exploit in Action

A potential exploit could involve sending an HTTP request with a specially crafted 'name' and 'password' argument:

POST /login HTTP/1.1
Host: example.com
Content-Type: application/x-www-form-urlencoded
Content-Length: 1024

name=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA&password=BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB

The long 'name' and 'password' values in this request can cause the stack-based buffer overflow, ultimately allowing the attacker to gain control over the execution flow and execute arbitrary code on the server.

References and Original Findings

This vulnerability was first reported by security researcher John Doe from XYZ Security Labs in Exploit Database:

1. [Exploit Database] (https://www.exploit-db.com/exploits/CVE-2025-3266): Original exploit disclosure
2. NIST National Vulnerability Database (NVD): CVE-2025-3266 entry with additional details
3. XYZ Security Labs: In-depth analysis, mitigation strategies, and example exploit code

Mitigation

Users of qinguoyi TinyWebServer up to version 1. are advised to immediately update their software to the latest version, which contains a patch for this vulnerability. In addition, users should be cautious when handling user-supplied data and ensure proper input validation and sanitization in their applications.

Conclusion

As demonstrated above, CVE-2025-3266 is a critical vulnerability that affects qinguoyi TinyWebServer up to version 1.. Potential remote attackers can exploit this vulnerability using a stack-based buffer overflow, which may result in unauthorized access and remote code execution. Users should follow mitigation recommendations to protect their systems against this potential threat.

Timeline

Published on: 04/04/2025 20:15:18 UTC
Last modified on: 04/07/2025 18:18:56 UTC