From:             bugs dot php dot net at chsc dot dk
Operating system: Linux
PHP version:      5.2.2
PHP Bug Type:     Safe Mode/open_basedir
Bug description:  open_basedir bypass via readfile()

Description:
------------
file_exists() etc. does not allow checking the existence of files outside
the directories specified in open_basedir.

Appearently readfile() does *not* have this restriction and thus allows
checking the existence of files anywhere in the filesystem. If
realpath($filename) returns a string (i.e. not false), the file exists.
This is a circumvention of the open_basedir restriction in file_exists()
etc.


Reproduce code:
---------------
The following should always be true, but it isn't when $dir is outside the
directories specified in open_basedir:

var_dump(file_exists($dir) === (bool) realpath($dir));



-- 
Edit bug report at http://bugs.php.net/?id=41492&edit=1
-- 
Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=41492&r=trysnapshot44
Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=41492&r=trysnapshot52
Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=41492&r=trysnapshot60
Fixed in CVS:                 http://bugs.php.net/fix.php?id=41492&r=fixedcvs
Fixed in release:             http://bugs.php.net/fix.php?id=41492&r=alreadyfixed
Need backtrace:               http://bugs.php.net/fix.php?id=41492&r=needtrace
Need Reproduce Script:        http://bugs.php.net/fix.php?id=41492&r=needscript
Try newer version:            http://bugs.php.net/fix.php?id=41492&r=oldversion
Not developer issue:          http://bugs.php.net/fix.php?id=41492&r=support
Expected behavior:            http://bugs.php.net/fix.php?id=41492&r=notwrong
Not enough info:              http://bugs.php.net/fix.php?id=41492&r=notenoughinfo
Submitted twice:              http://bugs.php.net/fix.php?id=41492&r=submittedtwice
register_globals:             http://bugs.php.net/fix.php?id=41492&r=globals
PHP 3 support discontinued:   http://bugs.php.net/fix.php?id=41492&r=php3
Daylight Savings:             http://bugs.php.net/fix.php?id=41492&r=dst
IIS Stability:                http://bugs.php.net/fix.php?id=41492&r=isapi
Install GNU Sed:              http://bugs.php.net/fix.php?id=41492&r=gnused
Floating point limitations:   http://bugs.php.net/fix.php?id=41492&r=float
No Zend Extensions:           http://bugs.php.net/fix.php?id=41492&r=nozend
MySQL Configuration Error:    http://bugs.php.net/fix.php?id=41492&r=mysqlcfg