[SOLVED] str_replace eval

[newbtophp]

I have the following code, everything works fine, but i can't get the str_replace to work, I think its because $file doesnt contain unset, but once executed (after the eval), it then prints unset.

 

So theirfore im unsure on where to place that line?

 

$file = file_get_contents('code.php');
$file = str_replace('<?php', '', $file);
$file = str_replace('<?', '', $file);
$file = str_replace('?>', '', $file);

$file = str_replace('unset', 'hello', $file);

eval($file);

[mikesta707]

what does the file variable look like?

[newbtophp]

what does the file variable look like?

 

$file = file_get_contents('code.php');

[newbtophp]

content of code.php:

 

<?php

eval(base64_decode('ZWNobyAidW5zZXQiOw=='));

?>

[mikesta707]

that is because this

base64_decode('ZWNobyAidW5zZXQiOw==')

 

which results in unset isn't executed when you call file_get_contents. the variable file looks like

 

$file = "eval(base64_decode('ZWNobyAidW5zZXQiOw=='));";

 

 

[newbtophp]

Yep, thats what i thought, but i cant modify code.php since its on a remote server (long story).

 

So is their a work around, to some how bypass the eval?, and do the replace. Because code.php will remain the same.

[mikesta707]

replace the base64_encoded version of unset with the base64_encoded version of hello.

 

$file = file_get_contents('code.php');
$file = str_replace('<?php', '', $file);
$file = str_replace('<?', '', $file);
$file = str_replace('?>', '', $file);

$file = str_replace(base64_encode('unset'), base64_encode('hello'), $file);

[newbtophp]

doesnt seem to work  :-\