CVE-2010-5280 Detail

CVE-2010-5280

CVE Descriptions

Directory traversal vulnerability in the Community Builder Enhanced (CBE) (com_cbe) component 1.4.8, 1.4.9, and 1.4.10 for Joomla! allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the tabname parameter in a userProfile action to index.php. NOTE: this can be leveraged to execute arbitrary code by using the file upload feature.

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-22	Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V2	7.5		AV:N/AC:L/Au:N/C:P/I:P/A:P	nvd@nist.gov

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

EPSS First.org

Exploit information

Exploit Database EDB-ID : 15222

Publication date : 2010-10-08 22h00 +00:00
Author : Delf Tonder
EDB Verified : Yes

Description: Joomla CBE suffers from a local file inclusion vulnerability. As CBE also offers file uploading functionality that allows to upload files that contain php-code, this can be used to execute arbitary system-commands on the host with the webservers privileges. Risk: High Affected versions: - CBE v1.4.10 - CBE v1.4.9 - CBE v1.4.8 (maybe older versions) Not affaceted: - CBE v1.4.11 (current) Vulnerable code: in cbe.php a file identified by the param "tabname" is included if the "ajaxdirekt" param is set, without sanatizing the value of "tabname" first: -- $ajaxdirekt = JRequest::getVar('ajaxdirekt', null); $tabname = JRequest::getVar('tabname', null); if ($ajaxdirekt) { $tabfile = JPATH_SITE.DS.'components'.DS.'com_cbe'.DS.'enhanced'.DS.$tabname.DS.$tabname.".php"; if (file_exists($tabfile)) { include_once($tabfile); } return; } -- Exploitation / poc: index.php?option=com_cbe&task=userProfile&user=23&ajaxdirekt=true&tabname=../../../CREDITS.php%00 will execute the CREDITS.php Addional attack-vectors: CBE offers a file-upload function for uploading user profile images. The uploaded file is not checked for beeing well-formed, it only needs to have the right mime-type and maybe (depends on profile-picture configuration) the right size, so we can embed php-code in the profile-picture. Lets say we have registered an account on the site with the user-id 23, then we can execute the backdoor by requesting: index.php?option=com_cbe&task=userProfile&user=23&ajaxdirekt=true&tabname=../../../images/cbe/23.gif%00 As we stay in the documents-root, we dont even have to worry about safe-mode directory restrictions, and using GIFs will bypass most of CBE's image pre-processing functions during file upload (except file- and image-size checks). Solutions: a) check if the contents of an uploaded file contains a php open-tag ('<?php') (requires that the php-short-open-tag option is disabled) b) Joomla offers several functions for accessing POST and GET params, i guess using getWord() instead of getVar() would be a better choice in this case. History: 04.10.2010 - vendor informed 07.10.2010 - vendor released fixed version 08.10.2010 - public disclosure Cheers Delf Tonder