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.