Security researchers have recently detected a new WordPress plugin vulnerability which is basically a cross-site request forgery (CSRF) to stored cross-site scripting (XSS) problem in Contact Form 7 Style. The vulnerability is an add-on to the well-known Contact Form 7 umbrella plugin that allows an attacker to induce a victim user to perform actions that they do not intend to.
Analysis shows that the plugin has been installed on more than 50,000 sites and it can impact these sites by injecting malicious JavaScripts. With the help of the plugin attackers can execute arbitrary JavaScripts on the victim website thereby affecting the browser of a victim user. Moreover researchers could not find any available patch.
Contact Form 7 is used to create contact forms used by websites. The vulnerable Contact Form 7 Style allows users to customize a site’s Cascading Style Sheets (CSS) code, which is used to dictate the appearance of WordPress-based websites without the knowledge of the user.
Since, the bug can only be exploited if the admin user performs an action authenticated to the vulnerable WordPress site, admins should always be very careful while clicking on any links. If the admin is unsure about a link or attachment they must use incognito windows in order to protect the site from being successfully exploited by CSRF vulnerabilities. Moreover, the users are advised to deactivate and remove the Contact Form 7 Style plugin and find a replacement as experts could not find a patch to fix the bug.