source: https://www.securityfocus.com/bid/47369/info

PhpAlbum.net is prone to a remote command-execution vulnerability because it fails to properly validate user-supplied input.

An attacker can exploit this issue to execute arbitrary commands within the context of the vulnerable process.

PhpAlbum.net 0.4.1-14_fix06 is vulnerable; other versions may also be affected. 

http://www.example.com/main.php?cmd=setup&var1=user&var3=1-file_put_contents('./x.xxx','xxxx')