Transliterator < 2.5.9 - Unauthenticated Stored Cross-Site Scripting via Comment Content via Predictable {rstr_keep} Placeholder

Description

The Transliterator – Multilingual and Multi-script Text Conversion plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via Predictable {rstr_keep} Placeholder in all versions up to, and including, 2.5.8 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The payload survives WordPress comment save-time sanitization because the tags and attributes used (such as a[title] and code) are permitted by the core comment kses allow-list, and the literal characters comprising the plugin's shortcode markers and placeholder tokens are not stripped.