The Anti-Spam by CleanTalk – Spam Protection Without CAPTCHA plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'user_email' parameter in all versions up to, and including, 6.89.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Successful exploitation requires user registration to be open on the site, and script execution is triggered when an Administrator subsequently runs the plugin's user-spam scan and views the resulting Non-checkable users or Spam users tab — the plugin's own documented workflow.
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
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 6
https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.89.1/i…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.89.1/l…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.89.1/l…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.89.1/l…
security@wordfence.com
https://plugins.trac.wordpress.org/changeset?reponame=&old=3747972%40cleantalk-…
security@wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/93cf8a35-61a4-4998-ae…
security@wordfence.com