Unauthenticated Arbitrary File Read via Null Byte Injection in DB Electronica Telecomunicazioni S.p.A. Mozart FM Transmitter versions 30, 50, 100, 300, 500, 1000, 2000, 3000, 3500, 6000, 7000 allows an attacker to perform Null byte injection in download_setting.php allows reading arbitrary files. The /var/tdf/download_setting.php endpoint constructs file paths by concatenating user-controlled $_GET['filename'] with a forced .tgz extension.

Running on PHP 5.3.2 (pre-5.3.4), the application is vulnerable to null byte injection (%00), allowing attackers to bypass the extension restriction and traverse paths. By requesting filename=../../../../etc/passwd%00, the underlying C functions treat the null byte as a string terminator, ignoring the appended .tgz and enabling unauthenticated arbitrary file disclosure of any file readable by the web server user.