The Gwolle Guestbook plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘gwollegbcontent’ parameter in all versions up to, and including, 4.9.2 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.
A vulnerability was found in Gwolle Guestbook Plugin 1.7.4. It has been rated as problematic. This issue affects some unknown processing. The manipulation leads to basic cross site scripting. The attack may be initiated remotely.