The WP Fastest Cache plug-in for optimizing the loading times of WordPress websites offered attack options for cross-site scripting (XSS) and SQL injection. An update is available for the more than one million users of the cache plugin: WP Fastest Cache 0.9.5 eliminates the in all previous versions existing security problems.
If you haven’t updated the plugin yet, you should do so as soon as possible. Those who discovered the vulnerabilities rate the security risk as “high” to “critical”. The secured version has been on the WP Fastest Cache download site available.
A Blog entry by the company Jetpack gives details of the two vulnerabilities, which strangely have the same CVE ID (CVE-2021-24869), but different descriptions and CVSS scores (7.7 / “High” and 9.6 / “Critical”).
The score 7.7 relates to a possibility of SQL injection, which only exists under certain conditions: The attacker must be logged in as a “normal” user and this must also be done in the attacked WP installation “Classic Editor” plugin installed. If these prerequisites are met, it is conceivable that sensitive data such as user names in combination with password hashes can be accessed.
The attack possibility rated 9.6 also exists without such restrictions, but requires user interaction with the website: In the course of a so-called Cross-Site-Request-Forgery attack, it is possible to carry out any actions with the rights of the administrator during the attack was registered. In addition, the attacker could permanently smuggle malicious code into the website in question, which could later be used for “Stored XSS” attacks, for example.