Description
Rack is a modular Ruby web server interface. Prior to versions 2.2.20, 3.1.18, and 3.2.3, `Rack::Request#POST` reads the entire request body into memory for `Content-Type: application/x-www-form-urlencoded`, calling `rack.input.read(nil)` without enforcing a length or cap. Large request bodies can therefore be buffered completely into process memory before parsing, leading to denial of service (DoS) through memory exhaustion. Users should upgrade to Rack version 2.2.20, 3.1.18, or 3.2.3, anu of which enforces form parameter limits using `query_parser.bytesize_limit`, preventing unbounded reads of `application/x-www-form-urlencoded` bodies. Additionally, enforce strict maximum body size at the proxy or web server layer (e.g., Nginx `client_max_body_size`, Apache `LimitRequestBody`).
Problem types
CWE-400: Uncontrolled Resource Consumption
Product status
>= 3.0, < 3.1.18
>= 3.2, < 3.2.3
References
github.com/rack/rack/security/advisories/GHSA-6xw4-3v39-52mm
github.com/...ommit/4e2c903991a790ee211a3021808ff4fd6fe82881
github.com/...ommit/cbd541e8a3d0c5830a3c9a30d3718ce2e124f9db
github.com/...ommit/e179614c4a653283286f5f046428cbb85f21146f
