SAP EP-RUNTIME 7.5 Denial Of Service

`Application: SAP EP-RUNTIME component  
  
Versions Affected: SAP EP-RUNTIME 7.5  
  
Vendor URL: http://SAP.com  
  
Bugs: Denial of Service  
  
Sent: 22.04.2016  
  
Reported: 23.04.2016  
  
Vendor response: 23.04.2016  
  
Date of Public Advisory: 12.07.2016  
  
Reference: SAP Security Note 2315788  
  
Author: Mathieu Geli (ERPScan)  
  
  
  
Description  
  
  
1. ADVISORY INFORMATION  
  
Title: [ERPSCAN-16-029] SAP NetWeaver AS JAVA a deserialization of  
untrusted user value  
  
Advisory ID: [ERPSCAN-16-029]  
  
Risk: High  
  
Advisory URL: https://erpscan.com/advisories/erpscan-16-029-sap-netweaver-java-7-5-deserialization-untrusted-user-value-trustmanagementservlet/  
  
Date published: 12.17.2016  
  
Vendors contacted: SAP  
  
  
2. VULNERABILITY INFORMATION  
  
Class: Denial of Service  
  
Impact: DoS  
  
Remotely Exploitable: Yes  
  
Locally Exploitable: No  
  
  
CVSS Information  
  
CVSS Base Score v3: 4.9 / 10  
  
CVSS Base Vector:  
  
AV : Attack Vector (Related exploit range) Network (N)  
  
AC : Attack Complexity (Required attack complexity) Low (L)  
  
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 None (N)  
  
I : Impact to Integrity None (N)  
  
A : Impact to Availability High (H)  
  
  
  
3. VULNERABILITY DESCRIPTION  
  
An attacker can use a special HTTP request in order to force a server  
to deserialize evil objects, which results in denial of service.  
  
  
4. VULNERABLE PACKAGES  
  
SAP EP-RUNTIME component  
  
  
5. SOLUTIONS AND WORKAROUNDS  
  
To correct this vulnerability, install SAP Security Note 2315788  
  
  
6. AUTHOR  
  
Mathieu Geli (ERPScan)  
  
  
  
7. TECHNICAL DESCRIPTION  
  
PoC  
  
Evil object in 'serial.cc3' as an attachment in this bug entry. It was  
generated with ysoserial framework, if the commons.collections jar was  
in the CLASSPATH we will have direct RCE.  
  
Now, we can only send DoS payloads that will trigger OutOfMemory  
exception on 7.5. Payload for that as attachment named 'serial.mem'.  
  
  
curl -v -XPOST --user 'user:password'  
http://172.16.30.29:50000/com.sap.portal.fpn.enterpriseservicesweb.mod/TrustManagementServlet  
--data-binary @serial.cc3  
  
This request will trigger a series of exceptions in server's log.  
  
The DoS payload will render the server unstable for some minutes with  
following exception:  
  
Server process shutting down with exit code [666] memory allocation  
error [OutOfMemoryError]  
java.lang.OutOfMemoryError: Requested array size exceeds VM limit  
(failed to allocate 8589934576 bytes) (array length 2147483639)  
  
  
8. REPORT TIMELINE  
  
Sent: 22.04.2016  
  
Reported: 23.04.2016  
  
Vendor response: 23.04.2016  
  
Date of Public Advisory: 12.07.2016  
  
  
  
9. REFERENCES  
  
https://erpscan.com/advisories/erpscan-16-029-sap-netweaver-java-7-5-deserialization-untrusted-user-value-trustmanagementservlet/  
  
  
10. ABOUT ERPScan Research  
  
ERPScan research team specializes in vulnerability research and  
analysis of critical enterprise applications. It was acknowledged  
multiple times by 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 of discovering new types of  
vulnerabilities (TOP 10 Web Hacking Techniques 2012) and of the "The  
Best Server-Side Bug" nomination at BlackHat 2013.  
  
ERPScan experts participated as speakers, presenters, and trainers at  
60+ prime international security conferences in 25+ countries across  
the continents ( e.g. BlackHat, RSA, HITB) and conducted private  
trainings for several Fortune 2000 companies.  
  
ERPScan researchers carry out the EAS-SEC project that is focused on  
enterprise application security awareness by issuing annual SAP  
security researches.  
  
ERPScan experts were interviewed in specialized infosec resources and  
featured in major media worldwide. Among them there are Reuters,  
Yahoo, SC Magazine, The Register, CIO, PC World, DarkReading, Heise,  
Chinabyte, etc.  
  
Our team consists of highly-qualified researchers, specialized in  
various fields of cybersecurity (from web application to ICS/SCADA  
systems), gathering their experience to conduct the best SAP security  
research.  
  
11. ABOUT ERPScan  
  
ERPScan is the most respected and credible Business Application  
Cybersecurity provider. Founded in 2010, the company operates globally  
and enables large Oil and Gas, Financial, Retail and other  
organizations to secure their mission-critical processes. Named as an  
aEmerging Vendora in Security by CRN, listed among aTOP 100 SAP  
Solution providersa 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.  
  
ERPScanas primary mission is to close the gap between technical and  
business security, and provide solutions for CISO's to evaluate and  
secure SAP and Oracle ERP systems and business-critical applications  
from both cyberattacks and internal fraud. As a rule, our clients are  
large enterprises, Fortune 2000 companies and MSPs, whose requirements  
are to actively monitor and manage security of vast SAP and Oracle  
landscapes on a global scale.  
  
We afollow the suna and have two hubs, located in Palo Alto and  
Amsterdam, to provide threat intelligence services, continuous support  
and to 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  
`