Inconsistent Interpretation of HTTP Requests in puma

CVE-2023-40175

What is CVE-2023-40175?

Puma, a parallel web server built on Ruby/Rack, has demonstrated an issue in processing HTTP requests that could lead to request smuggling. The vulnerability arises from improper handling of chunked transfer encoding bodies and zero-length Content-Length headers. Specifically, the server's failure to accurately parse trailing fields in chunked encoding or blank headers poses risks depending on how the website implements Puma. It is vital for users running versions older than 6.3.1 and 5.6.7 to upgrade promptly, as there are currently no known workarounds for mitigating this vulnerability.

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