The Unbounce Landing Pages plugin is vulnerable to an authorization bypass that allows authenticated users to redirect site traffic, posing a high risk of malicious content injection.

This flaw is classified as a missing authorization vulnerability (CWE-862) occurring because the plugin fails to perform capability checks during configuration updates. Any authenticated user, including low-privileged subscribers, can reconfigure the front-end proxy to point to an attacker-controlled host.

The ability to serve arbitrary content from the site origin carries significant risk to brand reputation and user trust. By manipulating the proxy configuration, an attacker can facilitate phishing campaigns or deliver malicious scripts to visitors, potentially leading to unauthorized data harvesting. With a CVSS score of 8.0, this vulnerability is considered High, as it provides a direct path for attackers to compromise the integrity and authenticity of the web application.

Immediate Action: Update the Unbounce Landing Pages plugin to version 1.1.5 or later immediately.

Proactive Monitoring: Audit WordPress user accounts and review plugin configuration logs for unauthorized changes to proxy settings.

Compensating Controls: Implement a Web Application Firewall (WAF) rule to block suspicious requests targeting the configuration update endpoints used by this plugin.

Public Exploit Available: No — there is no confirmed public exploit available.

Given the High severity of this vulnerability, immediate patching is required to prevent potential site defacement and phishing attacks. Administrators should verify that all instances of the Unbounce Landing Pages plugin are updated to version 1.1.5, as the lack of authorization controls makes this an attractive target for attackers seeking to compromise site integrity.