The vulnerability resides in the Passster WordPress plugin, versions prior to 4.2.24, where an AJAX endpoint fails to enforce authorization before returning the content of an item that has been password protected. As a result, anyone can retrieve the plaintext content by simply sending a request to that endpoint. This bypass falls under CWE‑863, an authorization bypass through user‑controlled input, and could be used by unauthenticated attackers to read confidential or sensitive post content.

WordPress sites that have installed the Passster plugin before version 4.2.24 are affected. The plugin is listed under the vendor name “Unknown:Passster” in the CNA data. Any installation that includes the vulnerable AJAX handler and has password‑protected content is potentially at risk. All earlier releases (for example, 4.2.23 and earlier) are included unless the site owner has manually patched or disabled the endpoint.

The CVSS base score of 5.3 indicates a moderate severity. The EPSS score is not available, so the likelihood of exploitation cannot be quantified, but the vulnerability is not listed in CISA’s KEV catalog, suggesting no known mass exploitation. The likely attack vector is that an unauthenticated user can craft an HTTP request to the AJAX URL, supply the necessary parameters, and receive the protected content. No authentication or privileged access is required, making it a low‑barrier attack for anyone with internet access to the site.