The Spam protection, Anti-Spam, FireWall by CleanTalk plugin for WordPress is vulnerable to unauthorized Arbitrary Plugin Installation due to an authorization bypass via reverse DNS (PTR record) spoofing on the 'checkWithoutToken' function in all versions up to, and including, 6.71. This makes it possible for unauthenticated attackers to install and activate arbitrary plugins which can be leveraged to achieve remote code execution if another vulnerable plugin is installed and activated. Note: This is only exploitable on sites with an invalid API key.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/trunk/lib/Cle…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/trunk/lib/Cle…
security@wordfence.com
https://plugins.trac.wordpress.org/changeset/3454488/cleantalk-spam-protect#fil…
security@wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/cb603be6-4a12-49e1-b8…
security@wordfence.com