fastify-swagger-ui is a Fastify plugin for serving Swagger UI. Prior to 2.1.0, the default configuration of `@fastify/swagger-ui` without `baseDir` set will lead to all files in the module's directory being exposed via http routes served by the module. The vulnerability is fixed in v2.1.0. Setting the `baseDir` option can also work around this vulnerability.

Swagger UI 4.1.2 and earlier could allow a remote attacker to conduct spoofing attacks. By persuading a victim to open a crafted URL, an attacker could exploit this vulnerability to display remote OpenAPI definitions. Note: This was originally claimed to be resolved in 4.1.3. However, third parties have indicated this is not resolved in 4.1.3 and even occurs in that version and possibly others.

An issue has been discovered in GitLab CE/EE affecting all versions starting from 12.6 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2. GitLab was vulnerable to HTML Injection through the Swagger UI feature.

A Cascading Style Sheets (CSS) injection vulnerability in Swagger UI before 3.23.11 allows attackers to use the Relative Path Overwrite (RPO) technique to perform CSS-based input field value exfiltration, such as exfiltration of a CSRF token value. In other words, this product intentionally allows the embedding of untrusted JSON data from remote servers, but it was not previously known that <style>@import within the JSON data was a functional attack method.