Package Instance

Rack has a Directory Traversal via Rack:Directory
`Rack::Directory`’s path check used a string prefix match on the expanded path. A request like `/../root_example/` can escape the configured root if the target path starts with the root string, allowing directory listing outside the intended root.

Rack: Multipart parser buffers large non‑file fields entirely in memory, enabling DoS (memory exhaustion)
`Rack::Multipart::Parser` stores non-file form fields (parts without a `filename`) entirely in memory as Ruby `String` objects. A single large text field in a multipart/form-data request (hundreds of megabytes or more) can consume equivalent process memory, potentially leading to out-of-memory (OOM) conditions and denial of service (DoS).

Rack's multipart parser buffers unbounded per-part headers, enabling DoS (memory exhaustion)
`Rack::Multipart::Parser` can accumulate unbounded data when a multipart part’s header block never terminates with the required blank line (`CRLFCRLF`). The parser keeps appending incoming bytes to memory without a size cap, allowing a remote attacker to exhaust memory and cause a denial of service (DoS).

Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion)
`Rack::Multipart::Parser` buffers the entire multipart **preamble** (bytes before the first boundary) in memory without any size limit. A client can send a large preamble followed by a valid boundary, causing significant memory use and potential process termination due to out-of-memory (OOM) conditions.

Rack has possible DoS Vulnerability with Range Header
# Possible DoS Vulnerability with Range Header in Rack

There is a possible DoS vulnerability relating to the Range request header in
Rack.  This vulnerability has been assigned the CVE identifier CVE-2024-26141.

Versions Affected:  >= 1.3.0.
Not affected:       < 1.3.0
Fixed Versions:     3.0.9.1, 2.2.8.1

Impact
------
Carefully crafted Range headers can cause a server to respond with an
unexpectedly large response. Responding with such large responses could lead
to a denial of service issue.

Vulnerable applications will use the `Rack::File` middleware or the
`Rack::Utils.byte_ranges` methods (this includes Rails applications).

Releases
--------
The fixed releases are available at the normal locations.

Workarounds
-----------
There are no feasible workarounds for this issue.

Patches
-------
To aid users who aren't able to upgrade immediately we have provided patches for
the two supported release series. They are in git-am format and consist of a
single changeset.

* 3-0-range.patch - Patch for 3.0 series
* 2-2-range.patch - Patch for 2.2 series

Credits
-------

Thank you [ooooooo_q](https://hackerone.com/ooooooo_q) for the report and
patch

Rack has a Possible Information Disclosure Vulnerability
A possible information disclosure vulnerability existed in `Rack::Sendfile` when running behind a proxy that supports `x-sendfile` headers (such as Nginx). Specially crafted headers could cause `Rack::Sendfile` to miscommunicate with the proxy and trigger unintended internal requests, potentially bypassing proxy-level access restrictions.