Description
WordPress Plugin WP Maintenance Mode & Site Under Construction is prone to a cross-site request forgery vulnerability. Exploiting this issue may allow a remote attacker to perform certain administrative actions and gain unauthorized access to the affected application; other attacks are also possible. WordPress Plugin WP Maintenance Mode & Site Under Construction version 1.8.2 is vulnerable; prior versions may also be affected.
Remediation
Edit the source code to ensure that CSRF protection is implemented with Nonce-like mechanism or disable the plugin until a fix is available
References
https://ithemes.com/wordpress-vulnerability-report-april-2021-part-4/
https://wordpress.org/plugins/wp-maintenance-mode-site-under-construction/#description
Related Vulnerabilities
WordPress Plugin Elementor Pro Cross-Site Scripting (2.0.9)
WordPress 4.2.x Multiple Vulnerabilities (4.2 - 4.2.26)
TYPO3 URL Redirection to Untrusted Site ('Open Redirect') Vulnerability (CVE-2010-3669)
WordPress Plugin Multiple Page Generator-MPG Cross-Site Request Forgery (3.3.9)
WordPress Plugin WP Support Plus Responsive Ticket System SQL Injection (7.1.4)