Public Vulnerability Reports

Tikiwiki tiki-user_preferences Command Injection Vulnerability



Tikiwiki Community Portal is a full featured, freely available,
Wiki/CMS/Groupware system written in PHP. More information is available


Remote exploitation of an input validation vulnerability in Tikiwiki
could allow attackers to gain access to arbitrary files on the
vulnerable system and execute arbitrary code under the privileges of the
underlying web-server.

The problem specifically exists in the following snippet of code from

    if (isset($_REQUEST["prefs"])) {
        if ($change_language == 'y') {
            if (isset($_REQUEST["language"])) {
                $tikilib->set_user_preference($userwatch, 'language',
                $smarty->assign('language', $_REQUEST["language"]);
                include ('lang/' . $_REQUEST["language"] .

No sanity checking is done on the 'language' parameter prior to
utilizing it in a call to the PHP function include(). By specifying a
path with directory traversal modifiers, an attacker can request an
arbitrary file to load and render on the screen.


Exploitation could allow authenticated remote attackers to access
arbitrary files on the vulnerable system with the privileges of the
underlying web-server. If external database access is allowed,
exploitation can result in a full database compromise since database
credentials are easily exposed through this vulnerability.

Exploitation can result in arbitrary command execution with the
privileges of the underlying targeted web server. This is possible
because attackers can generate request URLs with arbitrary script
directives that are recorded in the web server log files. Attackers can
then utilize the path to the poisoned log file in the file inclusion,
resulting in the directives being parsed and executed.


iDEFENSE has confirmed the existence of this issue in Tikiwiki versions
1.8.4 and 1.8.5. It is suspected that earlier versions are vulnerable as


Restrict anonymous access to Tikiwiki. If remote database connectivity
is not required, configure the underlying database server to bind to
localhost only or firewall the listening port to accept trusted hosts
only. Restrict read access of log files from the web server user.


This vulnerability has been addressed in Tikiwiki 1.9.1 which is
available for download at:


The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-1925 to this issue. This is a candidate for inclusion in
the CVE list (, which standardizes names for
security problems.


06/07/2005   Initial vendor notification
08/21/2005   Initial vendor response
11/10/2005   Public disclosure


This vulnerability was discovered by both Maciej Piotr Falkiewicz
(fingerout[at]gmail[dot]com) and an anonymous contributor.

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Copyright © 2005 Verisign, Inc.

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