Although the plug-in is no longer available, the Kaswara Modern WPBakery Page Builder Addons is still running on as many as 8,000 WordPress sites, according to analysts who warn the app's unpatched file upload vulnerability is under active attack.
The WordPress bug, tracked under CVE-2021-24284, can be used to upload malicious PHP files to an affected website, according to the research team at Wordfence. The vulnerability could lead to code execution and complete site takeover, the researchers warn. The plug-in was closed without a patch and the Wordfence team says all versions are affected by the bug.
The team stresses this is a "serious vulnerability that can lead to complete site takeover" and that the "developer has not been responsive regarding the patch" in their advisory on the WordPress plug-in. Since it is unlikely the plug-in will ever receive a patch for this critical vulnerability, "the best option is to fully remove the Kaswara Modern WPBakery Page Builder Addons plugin from your WordPress website," the researchers advise.