Kajona 4.7 – Cross-Site Scripting / Directory Traversal
Security Advisory - Curesec Research Team 1. Introduction Affected Product: Kajona 4.7 Fixed in: 5.0 Fixed Version Link: https://www.kajona.de/en/Downloads/downloads.get_kajona.html Vendor Website: https://www.kajona.de/ Vulnerability Type: XSS & Directory Traversal Remote Exploitable: Yes Reported to vendor: 04/11/2016 Disclosed to public: 09/15/2016 Release mode: Coordinated Release CVE: n/a Credits Tim Coen of Curesec GmbH 2. Overview Kajona is an open source CMS written in PHP. In version 4.7, it is vulnerable to multiple XSS attacks and limited directory traversal. The XSS vulnerabilities are reflected as well as persistent, and can lead to the stealing of cookies, injection of keyloggers, or the bypassing of CSRF protection. The directory traversal issue gives information about which files exist on a system, and thus allows an attacker to gather information about a system. 3. Details XSS 1: Reflected XSS CVSS: Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N The function that parses admin requests echoes user input into a JavaScript context without escaping, leading to reflected XSS. As the injection takes place into a JavaScript context, browser filters will generally not be able to filter out an attack. In the case of Kajona, XSS may lead to code execution, as admins can upload PHP files via the media manager. Proof of Concept: http://localhost/kajona/index.php?admin=1&module=search&action=search&peClose=1&peRefreshPage=';alert(1);foo=' Code: core/module_system/system/class_request_dispatcher.php $strReturn = "<html><head></head><body onload=\"parent.location = '" . urldecode(getGet("peRefreshPage")) . "';\"></body></html>"; XSS 2: Reflected XSS CVSS: Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N The media manager echoes the form_element parameter into a JavaScript context without escaping, leading to reflected XSS. As the injection takes place into a JavaScript context, browser filters will generally not be able to filter out an attack. Note that a valid systemid id is required. Proof of Concept: http://localhost/kajona/index.php?admin=1&module=mediamanager&action=folderContentFolderviewMode&systemid=[VALID_SYSTEM_ID]&form_element=']]);alert(1);KAJONA.admin.folderview.selectCallback([['# Click on "Accept" overlay of an image to trigger the injected code. XSS 3: Reflected XSS CVSS: Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N The "class_messageprovider_exceptions_enabled" parameter of the xml.php script is vulnerable to reflected XSS. Proof of Concept: http://localhost/kajona/xml.php?admin=1&module=messaging&action=saveConfigAjax&systemid=&class_messageprovider_exceptions_enabled=false<a xmlns%3aa%3d'http%3a%2f%2fwww.w3.org%2f1999%2fxhtml'><a%3abody onload%3d'alert(1)'%2f><%2fa>&messageprovidertype=class_messageprovider_exceptions XSS 4: Persistent XSS CVSS: Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N When creating a comment, the subject is vulnerable to persistent XSS. The click of an admin is required to execute the injected JavaScript code. Proof of Concept: 1. Leave a comment: http://localhost/kajona/index.php?page=postacomment 2. As subject, use: ');alert('1 3. Visit the comment overview: http://localhost/kajona/index.php?admin=1&module=postacomment&action=list 4. Click edit on the comment 5. Click on "Edit Tags" (the second symbol from the right) Directory Traversal When viewing images, the file name is improperly sanitized, allowing for directory traversal. It is not possible to actually read out files, as there are additional checks in place preventing that. But an unauthenticated attacker can still see which files exist on a system and which do not, making it possible to collect information for further attacks. Proof of Concept: GET /kajona/image.php?image=/files/images/upload/....//....//....//download.php&maxWidth=20&maxHeight=2 HTTP/1.1 -> 200 (but not shown) GET /kajona/image.php?image=/files/images/upload/....//....//....//foobar.php&maxWidth=20&maxHeight=2 HTTP/1.1 -> 404 Code: core/module_system/image.php public function __construct() { //find the params to use $this->strFilename = urldecode(getGet("image")); //avoid directory traversing $this->strFilename = str_replace("../", "", $this->strFilename); [...] } [...] private function resizeImage() { //Load the image-dimensions if(is_file(_realpath_ . $this->strFilename) && (uniStrpos($this->strFilename, "/files") !== false || uniStrpos($this->strFilename, "/templates") !== false)) { [...] } class_response_object::getInstance()->setStrStatusCode(class_http_statuscodes::SC_NOT_FOUND); class_response_object::getInstance()->sendHeaders(); } 4. Solution To mitigate this issue please upgrade at least to version 5.0: https://www.kajona.de/en/Downloads/downloads.get_kajona.html Please note that a newer version might already be available. 5. Report Timeline 04/11/2016 Informed Vendor about Issue 04/13/2016 Vendor applies fix to github 05/25/2016 Vendor releases fixed version 09/15/2016 Disclosed to public Blog Reference: https://www.curesec.com/blog/article/blog/Kajona-47-XSS-amp-Directory-Traversal-163.html -- blog: https://www.curesec.com/blog tweet: https://twitter.com/curesec Curesec GmbH Curesec Research Team Josef-Orlopp-StraAe 54 10365 Berlin, Germany |