A recently resolved vulnerability in the BackupBuddy WordPress plugin has been exploited in malicious attacks since late August, Defiant’s Wordfence team warns.
The BackupBuddy plugin, which has roughly 140,000 active installations, is meant to help WordPress site administrators easily manage their backup operations. The plugin allows users to store the backups to various online and local destinations.
Tracked as CVE-2022-31474 (CVSS score of 7.5), the exploited vulnerability exists because of an insecure method of downloading the backups for local storing, which allows any unauthenticated user to fetch files from the server.
Specifically, the plugin did not have capability checks or nonce validation implemented for the function meant for downloading local backup files, and also registered an admin_init hook for the function.
“This means that the function could be triggered via any administrative page, including those that can be called without authentication (admin-post.php), making it possible for unauthenticated users to call the function,” Wordfence explains.
Furthermore, because the backup path was not being validated, an attacker could supply an arbitrary file to be subsequently downloaded, the WordPress security firm says.
The security flaw impacts versions 22.214.171.124 to 126.96.36.199 of BackupBuddy and was fully resolved with a September 2 security update.
However, the first attacks targeting this vulnerability started roughly one week before the patch was released, with over 4.9 million exploitation attempts seen as of last week, Wordfence says.
Threat actors have been exploiting the flaw to obtain files storing sensitive information that can be used to further compromise the affected website.
“Due to the fact that this is an actively exploited vulnerability, we strongly encourage you to ensure your site has been updated to the latest patched version 8.7.5 which iThemes has made available to all site owners running a vulnerable version regardless of licensing status,” the WordPress security firm notes.
Wordfence has shared indicators of compromise (IoCs) to help site owners and administrators identify attacks, and recommends that they check their installations for a potential compromise.