Security researchers have detected a massive campaign that scanned close to 1.6 million WordPress sites for the presence of a vulnerable plugin that allows uploading files without authentication.
The attackers are targeting the Kaswara Modern WPBakery Page Builder, which has been abandoned by its author before receiving a patch for a critical severity flaw tracked as CVE-2021-24284.
The vulnerability would allow an unauthenticated attacker to inject malicious Javascript to sites using any version of the plugin and perform actions like uploading and deleting files, which could lead to complete takeover of the site.
While the size of the campaign is impressive, with 1,599,852 unique sites being targeted, only a small portion of them are running the vulnerable plugin.
Researchers at Defiant, the maker of the Wordfence security solution for WordPress, observed an average of almost half a million attack attempts per day against customer sites they protect.
Indistinct large-scale attacks
Based on Wordfence telemetry data, the attacks started on July 4 and continue to this day. and are still ongoing today at an average of 443,868 attempts every day.
Source and more details: https://www.bleepingcomputer.com/news/security/attackers-scan-16-million-wordpress-sites-for-vulnerable-plugin/