Package Instance

sinatra does not validate expanded path matches
Sinatra before 2.2.0 does not validate that the expanded path matches public_dir when serving static files.

Sinatra vulnerable to Reflected File Download attack
### Description
An issue was discovered in Sinatra 2.0 before 2.2.3 and 3.0 before 3.0.4. An application is vulnerable to a reflected file download (RFD) attack that sets the Content-Disposition header of a response when the filename is derived from user-supplied input.

### References
* https://www.blackhat.com/docs/eu-14/materials/eu-14-Hafif-Reflected-File-Download-A-New-Web-Attack-Vector.pdf
* https://github.com/advisories/GHSA-8x94-hmjh-97hq

Sinatra is vulnerable to ReDoS through ETag header value generation
There is a denial of service vulnerability in the `If-Match` and `If-None-Match` header parsing component of Sinatra, if the `etag` method is used when constructing the response and you are using Ruby < 3.2.

Sinatra vulnerable to Reliance on Untrusted Inputs in a Security Decision
Versions of the package sinatra from 0.0.0 are vulnerable to Reliance on Untrusted Inputs in a Security Decision via the X-Forwarded-Host (XFH) header. When making a request to a method with redirect applied, it is possible to trigger an Open Redirect Attack by inserting an arbitrary address into this header. If used for caching purposes, such as with servers like Nginx, or as a reverse proxy, without handling the X-Forwarded-Host header, attackers can potentially exploit Cache Poisoning or Routing-based SSRF.

Cross-site Scripting
Sinatra has XSS via the Bad Request page that occurs upon a params parser exception.

Path traversal on Windows
Path traversal is possible via backslash characters on Windows. An attacker could access arbitrary files and directories stored on the file system.