via wptavern.com => original post link
The LiteSpeed Cache plugin, used on more than four million WordPress sites, has patched an XSS vulnerability in version 5.7. The plugin provides all-in-one site acceleration capabilities, server-level caching, and a collection of optimization features. It is compatible with WordPress multisite, and popular plugins like WooCommerce, bbPress, and Yoast SEO, which may contribute to its popularity.
Wordfence security researcher István Márton discovered the XSS vulnerability and responsibly disclosed it to the LiteSpeed Cache Team on August 14, 2023. The Wordfence advisory describes how the vulnerability might make it possible for an attacker to inject malicious scripts:
The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘esi’ shortcode in versions up to, and including, 5.6 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.