The W3 Total Cache plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the is_w3tc_admin_page function in all versions up to, and including, 2.8.1. This makes it possible for authenticated attackers, with Subscriber-level access and above, to obtain the plugin's nonce value and perform unauthorized actions, resulting in information disclosure, service plan limits consumption as well as making web requests to arbitrary locations originating from the web application that can be used to query information from internal services, including instance metadata on cloud-based applications.
The W3 Total Cache plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on several functions in all versions up to, and including, 2.8.1. This makes it possible for unauthenticated attackers to deactivate the plugin as well as activate and deactivate plugin extensions.
The W3 Total Cache plugin for WordPress is vulnerable to Information Exposure in all versions up to, and including, 2.8.1 through the publicly exposed debug log file. This makes it possible for unauthenticated attackers to view potentially sensitive information in the exposed log file. For example, the log file may contain nonce values that can be used in further CSRF attacks.
Note: the debug feature must be enabled for this to be a concern, and it is disabled by default.
The W3 Total Cache plugin for WordPress is vulnerable to Sensitive Information Exposure in versions up to, and including, 2.7.5 via Google OAuth API secrets stored in plaintext in the publicly visible plugin source. This can allow unauthenticated attackers to impersonate W3 Total Cache and gain access to user account information in successful conditions. This would not impact the WordPress users site in any way.
The W3 Total Cache WordPress plugin before 2.1.4 was vulnerable to a reflected Cross-Site Scripting (XSS) security vulnerability within the "extension" parameter in the Extensions dashboard, which is output in an attribute without being escaped first. This could allow an attacker, who can convince an authenticated admin into clicking a link, to run malicious JavaScript within the user's web browser, which could lead to full site compromise.
The W3 Total Cache WordPress plugin before 2.1.5 was affected by a reflected Cross-Site Scripting (XSS) issue within the "extension" parameter in the Extensions dashboard, when the 'Anonymously track usage to improve product quality' setting is enabled, as the parameter is output in a JavaScript context without proper escaping. This could allow an attacker, who can convince an authenticated admin into clicking a link, to run malicious JavaScript within the user's web browser, which could lead to full site compromise.
The W3 Total Cache WordPress plugin before 2.1.3 did not sanitise or escape some of its CDN settings, allowing high privilege users to use JavaScript in them, which will be output in the page, leading to an authenticated Stored Cross-Site Scripting issue