Apache Sling Framework v2.3.6 - Information Disclosure Vulnerability

[Vulnerability Lab <research () vulnerability-lab com>]

Document Title:
===============
Apache Sling Framework v2.3.6 - Information Disclosure Vulnerability


References (Source):
====================
http://www.vulnerability-lab.com/get_content.php?id=1536

Adobe Bulletin: https://helpx.adobe.com/security/products/experience-manager/apsb16-05.html

http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-0956

Vulnerability Magazine: 
http://magazine.vulnerability-db.com/?q=articles/2016/02/10/apache-sling-fw-v236-remote-slingpostservlet-exception-vulnerability


CVE-ID:
=======
CVE-2016-0956


Release Date:
=============
2016-02-10


Vulnerability Laboratory ID (VL-ID):
====================================
1536


Common Vulnerability Scoring System:
====================================
6.4


Product & Service Introduction:
===============================
Apache Sling is a web framework that uses a Java Content Repository, such as Apache Jackrabbit, to store and manage 
content. Sling applications use either scripts 
or Java servlets, selected based on simple name conventions, to process HTTP requests in a RESTful way. The embedded 
Apache Felix OSGi framework and console provide 
a dynamic runtime environment, where code and content bundles can be loaded, unloaded and reconfigured at runtime. As 
the first web framework dedicated to JSR-170 
Java Content Repositories, Sling makes it very simple to implement simple applications, while providing an 
enterprise-level framework for more complex applications.

(Copy of the Vendor Homepage:  http://sling.apache.org/)


Adobe Experience Manager (AEM) provides a complete suite of applications for the Web Experience Management (WEM) of 
organizations.

(Copy of the Vendor Homepage: https://docs.adobe.com/docs/en/aem/6-1.html )


Abstract Advisory Information:
==============================
The Vulnerability Laboratory Core Research Team discovered a remote vulnerability in the official Apache Sling Framwork 
v2.3.6 software.


Vulnerability Disclosure Timeline:
==================================
2016-02-10:     Public Disclosure (Vulnerability Laboratory)


Discovery Status:
=================
Published


Affected Product(s):
====================
Apache Software Foundation
Product: Apache Sling - Framework (Adobe AEM) 2.3.6


Exploitation Technique:
=======================
Remote


Severity Level:
===============
High


Technical Details & Description:
================================
It seems that on some instances of AEM, due to lack of proper security controls and or misconfiguration, it is possible 
for remote unauthenticated 
users to enumerate local system files/folders that arent accessible publicly to unauthenticated users.

This can be achieved by sending a `delete` requests to the SlingPostServlet which in return, responds back with a 500 
exception page and the 
following exception message: (org.apache.sling.api.resource.PersistenceException - Unable to commit changes to session)

No actual files are deleted with this request however, the HTML response contains a `ChangeLog` field which is where 
all enumerated folder/file 
names are displayed (if existing). For instance, following POC command can be used to reproduce the said behavior.

curl -F``:operation=delete`` -F``:applyTo=/foldername/*`` http://website.com/path/file.html

To reproduce this in real world, I found an adobe website which is currently affected with this behavior. You can use 
the following CURL command 
to reproduce the POC:

curl -F``:operation=delete`` -F``:applyTo=/etc/*`` https://www.adobedemo.com/content/adobedemolab/welcome-page.html

Note: This curl command should enumerate all files/folders which currently exist in /etc folder

This vulnerability currently affects major websites i.e. almost every instance of Adobe AEM published on the internet. 
Some references are included below for reference.

Affected Framework(s):
Apache Sling

Affected Product(s)
Adobe AEM (All Versions)


Proof of Concept (PoC):
=======================
The security vulnerability can be exploited by remote attackers without privilege system user account or user 
interaction.
For security demonstration or to reproduce the vulnerability follow the provided information and steps below to 
continue.

PoC:
1. curl -F":operation=delete" -F":applyTo=/foldername/*" http://website.com/path/file.html
2. curl -F":operation=delete" -F":applyTo=/etc/*" https://www.adobedemo.com/content/adobedemolab/welcome-page.html


Solution - Fix & Patch:
=======================
The vulnerability is fixed in version Servlets POST 2.3.8. Please update by by automatic request or implement the 
manual fix.

Adobe: Hot fix 6445 resolves an information disclosure vulnerability affecting Apache Sling Servlets Post 2.3.6 
(CVE-2016-0956).


Security Risk:
==============
The security risk of the exception software vulnerability in the apache sling framework is estimated as high. (CVSS 6.4)


Credits & Authors:
==================
Vulnerability Laboratory [Research Team] - Ateeq Khan (ateeq () evolution-sec com) [www.vulnerability-lab.com] 
(https://twitter.com/cybercrimenews)


Disclaimer & Information:
=========================
The information provided in this advisory is provided as it is without any warranty. Vulnerability Lab disclaims all 
warranties, either expressed 
or implied, including the warranties of merchantability and capability for a particular purpose. Vulnerability-Lab or 
its suppliers are not liable 
in any case of damage, including direct, indirect, incidental, consequential loss of business profits or special 
damages, even if Vulnerability-Lab 
or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or 
limitation of liability for 
consequential or incidental damages so the foregoing limitation may not apply. We do not approve or encourage anybody 
to break any vendor licenses, 
policies, deface websites, hack into databases or trade with fraud/stolen material.

Domains:    www.vulnerability-lab.com           - www.vuln-lab.com                                      - 
www.evolution-sec.com
Contact:    admin () vulnerability-lab com      - research () vulnerability-lab com                     - admin () 
evolution-sec com
Section:    magazine.vulnerability-db.com       - vulnerability-lab.com/contact.php                     - 
evolution-sec.com/contact
Social:     twitter.com/#!/vuln_lab             - facebook.com/VulnerabilityLab                         - 
youtube.com/user/vulnerability0lab
Feeds:      vulnerability-lab.com/rss/rss.php   - vulnerability-lab.com/rss/rss_upcoming.php            - 
vulnerability-lab.com/rss/rss_news.php
Programs:   vulnerability-lab.com/submit.php    - vulnerability-lab.com/list-of-bug-bounty-programs.php - 
vulnerability-lab.com/register/

Any modified copy or reproduction, including partially usages, of this file requires authorization from Vulnerability 
Laboratory. Permission to 
electronically redistribute this alert in its unmodified form is granted. All other rights, including the use of other 
media, are reserved by 
Vulnerability-Lab Research Team or its suppliers. All pictures, texts, advisories, source code, videos and other 
information on this website 
is trademark of vulnerability-lab team & the specific authors or managers. To record, list (feed), modify, use or edit 
our material contact 
(admin () vulnerability-lab com or research () vulnerability-lab com) to get a permission.

                                Copyright © 2016 | Vulnerability Laboratory - [Evolution Security GmbH]™



-- 
VULNERABILITY LABORATORY - RESEARCH TEAM
SERVICE: www.vulnerability-lab.com
CONTACT: research () vulnerability-lab com