Thrive Optimize - Authentication Bypass (CVE-2021-24219)
93Exploiting IPs reported
The Thrive Optimize WordPress plugin before 1.4.13.3, Thrive Comments WordPress plugin before 1.4.15.3, Thrive Headline Optimizer WordPress plugin before 1.3.7.3, Thrive Leads WordPress plugin before 2.3.9.4, Thrive Ultimatum WordPress plugin before 2.3.9.4, Thrive Quiz Builder WordPress plugin before 2.3.9.4, Thrive Apprentice WordPress plugin before 2.3.9.4, Thrive Visual Editor WordPress plugin before 2.6.7.4, Thrive Dashboard WordPress plugin before 2.3.9.3, Thrive Ovation WordPress plugin before 2.4.5, Thrive Clever Widgets WordPress plugin before 1.57.1 and Rise by Thrive Themes WordPress theme before 2.0.0, Ignition by Thrive Themes WordPress theme before 2.0.0, Luxe by Thrive Themes WordPress theme before 2.0.0, FocusBlog by Thrive Themes WordPress theme before 2.0.0, Minus by Thrive Themes WordPress theme before 2.0.0, Squared by Thrive Themes WordPress theme before 2.0.0, Voice WordPress theme before 2.0.0, Performag by Thrive Themes WordPress theme before 2.0.0, Pressive by Thrive Themes WordPress theme before 2.0.0, Storied by Thrive Themes WordPress theme before 2.0.0, Thrive Themes Builder WordPress theme before 2.2.4 register a REST API endpoint associated with Zapier functionality. While this endpoint was intended to require an API key in order to access, it was possible to access it by supplying an empty api_key parameter in vulnerable versions if Zapier was not enabled. Attackers could use this endpoint to add arbitrary data to a predefined option in the wp_options table.
CrowdSec analysis
CVE-2021-24219 is a vulnerability affecting multiple Thrive Themes WordPress plugins and themes, where a REST API endpoint intended for Zapier integration could be accessed without proper authentication by supplying an empty API key. This flaw allows unauthenticated attackers to add arbitrary data to a predefined option in the WordPress wp_options table, potentially leading to unauthorized configuration changes or data manipulation. Exploiting this vulnerability could enable attackers to tamper with site settings or introduce malicious data, impacting the integrity of affected WordPress sites.
CrowdSec has been tracking this vulnerability and its exploits since 15th of October 2025.
Insights from the CrowdSec network reveal that the attackers trying to exploit CVE-2021-24219 are composed of a fairly even mix of opportunistic and targeted actors. Some attackers employ preliminary reconnaissance, while others use indiscriminate scanning. Telemetry from the CrowdSec network also shows that exploitation activity for CVE-2021-24219 remains steady week-over-week. Attack volumes are consistent with long-term trends, indicating sustained interest from threat actors. CVE-2021-24219 continues to be an active part of the threat landscape and will likely remain this way for the forseeable future.
Attackers exploit the unauthenticated /wp-json/td/v1/optin/subscription REST API endpoint by sending POST requests with an empty api_key parameter, allowing arbitrary updates to WordPress options without proper authorization.
Exploitation
Get real-time information about exploitation attempts and actors involved.
Common Weakness Enumeration (CWE)
Protection
Find out relevant information to protect your stack against this CVE.
Blocklist
With our advanced worldwide network detection, CrowdSec can provide a list of IPs known for exploiting the vulnerability.
To increase your protection against this CVE, block exploitation attempts with this list of identified actors.