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How the mentioned CVE works:
The vulnerability CVE-2025-64053 is a classic buffer overflow in the web management interface of Fanvil x210 devices running firmware version 2.12.20. The flaw resides in the `/cgi-bin/webconfig?page=upload&action=submit` endpoint, which handles POST requests for file uploads or configuration changes. The application fails to perform proper bounds checking on the data received in the HTTP POST request. When an attacker sends a specially crafted POST packet with an excessive amount of data, it overflows the fixed-size memory buffer (stack or heap) allocated for this operation. This corruption can overwrite adjacent memory structures, including critical function return pointers or exception handler addresses. By precisely controlling the overflow data, an attacker can manipulate these pointers to redirect the device’s execution flow. The end goal is to jump to and execute malicious shellcode (arbitrary commands) embedded within the attacker’s payload, which was part of the crafted request. Successful exploitation leads to a denial of service by crashing the service or, more severely, allows the attacker to execute operating system commands with the privileges of the vulnerable process, potentially gaining full control over the IP phone.
DailyCVE Form:
Platform: Fanvil x210
Version: 2.12.20
Vulnerability: Buffer Overflow
Severity: Not Specified
Date: 12/05/2025
Prediction: Patch not announced
What Undercode Say:
Analytics
No specific bash commands or exploit code were detailed in the provided . Analysis would involve fuzzing the target endpoint with oversized and malformed POST requests.
How Exploit:
- Identify a target Fanvil x210 device with web access.
- Craft an HTTP POST request to the endpoint
/cgi-bin/webconfig?page=upload&action=submit. - Structure the request body with payload data sized to exceed the application’s internal buffer.
- Include carefully constructed shellcode within the payload to overwrite a return address and gain command execution.
- Send the malicious request to the device to trigger the buffer overflow and potentially establish a reverse shell.
Protection from this CVE
Apply vendor firmware update when released. Until a patch is available, restrict network access to the device’s web interface, use strong network segmentation, and monitor logs for exploit attempts targeting the specific endpoint.
Impact:
Denial of Service (crash) or remote execution of arbitrary commands, leading to full device compromise.
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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