WP Content Security Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the WP Content Security Plugin for WordPress, affecting all versions through 2.3. The issue arises from inadequate input sanitization and output escaping, allowing unauthenticated attackers to inject arbitrary web scripts. These scripts are executed when users access the compromised pages.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, where injected scripts are executed in the context of the user viewing the page.

Reproduction

The vulnerability can be reproduced by injecting a script into the 'blocked-uri' or 'effective-directive' fields of the WordPress REST API. This can be done by sending a POST request to the '/wp-json/wpcsp/v1/route/LogPolicyViolation' endpoint, including the malicious script in the CSP report data. Once the script is injected, it will be executed whenever a user accesses the page where the script was injected.

Remediation

No known patch is available. It is recommended to uninstall the affected plugin and find a replacement.