Typo3 v4.5-4.7 Remote Code Execution (RFI/LFI)

[SirGod]

Typo3 e un script foarte folosit. Problema este ca pentru a exploata vulnerabilitatea e nevoie de register_globals ON (sanse mici spre foarte mici).

# Exploit Title: Typo3 v4.5-4.7 - Remote Code Execution (RFI/LFI)

# Date: 4th January 2012

# Author: MaXe

# Software Link: https://typo3.org/download/

# Version: 4.5.0 up to 4.5.8, 4.6.0 and 4.6.1 (+ development releases of

4.7 branch)

Typo3 v4.5-4.7 - Remote Code Execution (RFI/LFI)

Versions Affected: 4.5.0 up to 4.5.8, 4.6.0 and 4.6.1 (+ development

releases of 4.7 branch)

Info:

TYPO3 is a small to midsize enterprise-class Content Management Framework

offering

the best of both worlds: out-of-the-box operation with a complete set of

standard

modules and a clean and sturdy high-performance architecture accomodating

virtually

every kind of custom solution or extension.

External Links:

TYPO3 - the Enterprise Open Source CMS: Home

Credits: Björn Pedersen and Christian Toffolo who discovered and reported

the issue and the Security Team member Helmut Hummel for providing the

patch.

(This advisory was rewritten by MaXe @InterN0T to offer a quick overview

of the vulnerability, including the removal of all irrelevant and untrue

details.

-:: The Advisory ::-

Requirements for any RCE:

- register_globals in the php.ini MUST be enabled (if the exploit fails

against a supposed to be vulnerable version, this is why. This setting is

often disabled by default.)

Requirements for RFI:

- allow_url_include has to be enabled (It's often "off" by default.)

Proof of Concept:

By browsing to a script / page, that uses the following file:

typo3/sysext/workspaces/Classes/Controller/AbstractController.php (direct

access may not be allowed)

It is possible to include PHP code to be executed via the "BACK_PATH"

global variable. This can be accessed in ways like:

AbstractController.php?BACK_PATH=LFI/RFI

The vulnerable piece of code: require_once($GLOBALS['BACK_PATH'] .

'template.php');

Demonstrates, that it is necessary to append a null-byte ( ) after the

maliciously crafted input / URL. (Unless your remote file if applicable, is

named something.template.php)

-:: Solution ::-

* Update to the latest version of Typo3 OR change the vulnerable piece of

code to: require_once(PATH_site . TYPO3_mainDir . 'template.php');

References:

- http://typo3.org/fileadmin/security-team/bug32571/32571.diff

-

https://typo3.org/teams/security/security-bulletins/typo3-core/typo3-core-sa-2011-004/

-

news.typo3.org: Important Security-Bulletin Pre-Announcement