The WP Database Backup plugin for WordPress is vulnerable to OS Command Injection in versions before 5.2 via the mysqldump function. This vulnerability allows unauthenticated attackers to execute arbitrary commands on the host operating system.
The WP User plugin for WordPress is vulnerable to Stored Cross-Site Scripting via its settings parameters in versions up to, and including, 7.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.
The WP Database Backup WordPress plugin before 5.9 does not escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks when the unfiltered_html capability is disallowed (for example in multisite setup)
The WP Database Backup plugin through 5.5 for WordPress stores downloads by default locally in the directory wp-content/uploads/db-backup/. This might allow attackers to read ZIP archives by guessing random ID numbers, guessing date strings with a 2020_{0..1}{0..2}_{0..3}{0..9} format, guessing UNIX timestamps, and making HTTPS requests with the complete guessed URL.