Trustwave SpiderLabs Security Advisory TWSL2021-013: 
Authenticated SQL Injection in WordPress Plugin Stop Bad Bots

Published: 09/10/2021
Version: 1.1

Vendor: Bill Minozzi (https://stopbadbots.com/)
Product: WordPress Plugin Stop Bad Bots
Version affected:  <= 6.59

Product description:
The plugin provides functionality to limit bot access to the web site.

Finding 1: Authenticated SQL Injection
*****Credit: Martin Vierula of Trustwave
CVE: CVE-2021-24727
CWE: CWE-89

The plugin includes three pages: 
'Bad Bots Table' (page=sbb_my-custom-submenu-page)
'Bad IPs Table' (page=sbb_my-custom-submenu-page2)
'Bad Referer Table' (page=sbb_my-custom-submenu-page3)

All three of these pages are vulnerable to Authenticated Blind SQL Injection through both the 'order' and 'orderby' parameters.  Based on the capabilities check that is in place, ordinarily only high-auth users would be able to exploit this.

The following PoC outlines a time-based version of exploiting the vulnerability in the first of those pages via the 'order' parameter:

GET /wp-admin/admin.php?page=sbb_my-custom-submenu-page3&order=ASC%2C%28SELECT+%2A+FROM+%28SELECT%28SLEEP%288%29%29%29a%29-- HTTP/1.1

The following PoC outlines a time-based version of exploiting the vulnerability in the first of those pages via the 'orderby' parameter:

GET /wp-admin/admin.php?page=sbb_my-custom-submenu-page3&orderby=botnickname,%28SELECT%20*%20FROM%20%28SELECT%28SLEEP%288%29%29%29a%29%23 HTTP/1.1

Remediation Steps:
Upgrade the WordPress Plugin Stop Bad Bots to version 6.60 or the latest stable version.

Revision History:
07/21/2021 - Disclosed finding to vendor
08/02/2021 - Vendor releases fix
08/06/2021 - Advisory verson 1.0 published
09/10/2021 - CVE assigned
09/10/2021 - Advisory version 1.1 published

References
1. https://wordpress.org/plugins/stopbadbots/#developers

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application security tests globally. In addition, the SpiderLabs Research
team provides intelligence through bleeding-edge research and proof of
concept tool development to enhance Trustwave's products and services.
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