The Link Library WordPress plugin before 7.9.6 does not sanitise and escape a link field before outputting it inside an attribute of a link preview, allowing users with the Contributor role and above to perform Stored Cross-Site Scripting attacks. The preview is generated without authentication and without checking whether the link has been published, so an unapproved submission is enough to reach any visitor who opens it.
The Link Library plugin for WordPress is vulnerable to time-based SQL Injection via the 'linkurl' parameter in all versions up to, and including, 7.9.2 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.
The Link Library WordPress plugin before 7.9.6 does not sanitize a user-supplied destination folder before writing a generated image to disk, allowing users with the Contributor role and above to create directories and write or overwrite image files anywhere the web server can write, including outside the site's document root.
The written file name is always numeric with a fixed image extension, so executable code cannot be planted this way.
The Link Library plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Link Additional Parameters in all versions up to, and including, 7.7.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.