note 89163 deleted from function.exit by danbrown

Note Submitter: jbNULLezorg at NULLgmail dot com ---- To: rich dot lovely at klikzltd dot co dot uk, You may want to look at Filesystem Security > Null bytes related issues > Example #1 Script vulnerable to null bytes. Null bytes related issues As PHP uses the underlying C functions for filesystem related operations, it may handle null bytes in a quite unexpected way. As null bytes denote the end of a string in C, strings containing them won't be considered entirely but rather only until a null byte occurs. The following example shows a vulnerable code that demonstrates this problem: <?php $file = $_GET['file']; // "../../etc/passwd\0" if (file_exists('/home/wwwrun/'.$file.'.php')) { // file_exists will return true as the file /home/wwwrun/../../etc/passwd exists include '/home/wwwrun/'.$file.'.php'; // the file /etc/passwd will be included } ?>