The Wordfence Threat Intelligence team has been monitoring an ongoing exploit campaign targeting a recently disclosed vulnerability in WooCommerce Payments, a plugin installed on over 600,000 sites. Large-scale attacks against the vulnerability, assigned CVE-2023-28121, began on Thursday, July 14, 2023 and continued over the weekend, peaking at 1.3 million attacks against 157,000 sites on Saturday, July 16, 2023.
The exploit allows unauthenticated attackers to obtain administrative privileges on vulnerable websites, rating it a Critical CVSS score of 9.8. This makes it an appealing target, and this attack campaign confirms our original coverage of the vulnerability that predicted large-scale attacks.
All Wordfence users, including Wordfence free users, have been protected against this vulnerability since April 22, 2023 via a Firewall rule we developed to block exploit attempts. Wordfence Premium, Care, and Response sites received protection even earlier, on March 23, 2023. Versions 4.8.0 – 5.6.1 of the WooCommerce Payments plugin are vulnerable.
Readers can continue watching this and other trends on the Wordfence Intelligence dashboard, where it is currently the most heavily-attacked unique WordPress vulnerability.
Unlike many other large-scale campaigns which typically attack millions of sites indiscriminately, this one seems to be targeted against a smaller set of websites. What’s particularly interesting is that we began seeing early warning signs several days before the main wave of attacks – an increase in plugin enumeration requests searching for a
readme.txt file in the
wp-content/plugins/woocommerce-payments/ directory of millions of sites.