ReDoS Vulnerability in Rack::Multipart handle_mime_head

Summary

There is a denial of service vulnerability in the Content-Disposition parsing component of Rack. This is very similar to the previous security issue CVE-2022-44571.

Details

Carefully crafted input can cause Content-Disposition header parsing in Rack to take an unexpected amount of time, possibly resulting in a denial of service attack vector. This header is used typically used in multipart parsing. Any applications that parse multipart posts using Rack (virtually all Rails applications) are impacted.

Credits

Thanks to scyoon for reporting this to the Rails security team