Page Builder Gutenberg Blocks – CoBlocks Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the Page Builder Gutenberg Blocks – CoBlocks plugin for WordPress, affecting all versions through 3.1.16. The issue arises from inadequate output escaping of event titles, descriptions, and locations retrieved from external iCal feeds, specifically within the Events block rendering function. This vulnerability allows authenticated attackers with Contributor-level access or higher to inject arbitrary web scripts into pages, which are executed when users access the affected page.

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

To reproduce this vulnerability, an authenticated user with Contributor-level access or higher can inject scripts by providing malicious data in the event titles, descriptions, or locations through an external iCal feed. Once the data is processed by the Events block, the injected scripts will be executed when the page is viewed.

Remediation

Users are advised to update the CoBlocks plugin to version 3.1.17 or later, where this vulnerability has been patched.