Reading Progressbar WordPress Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the Reading Progressbar WordPress plugin, affecting versions prior to 1.3.1. The issue arises because the plugin fails to properly sanitize and escape certain settings. This flaw enables high-privilege users, such as administrators, to execute stored cross-site scripting attacks, even in environments where the unfiltered_html capability is restricted, such as multisite setups.

Impact

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

Reproduction

To reproduce this vulnerability, navigate to the Reading Progressbar settings. Enter a payload, such as a script injection, into the 'Progressbar height (pixels)' and 'Target fixed HTML element class/id to stick the bar on its bottom' fields, then save the settings.

Remediation

Users are advised to update the Reading Progressbar WordPress plugin to version 1.3.1 or later.