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CVE-2025-61770 Detail

Description

Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, `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. Remote attackers can trigger large transient memory spikes by including a long preamble in multipart/form-data requests. The impact scales with allowed request sizes and concurrency, potentially causing worker crashes or severe slowdown due to garbage collection. Versions 2.2.19, 3.1.17, and 3.2.2 enforce a preamble size limit (e.g., 16 KiB) or discard preamble data entirely. Workarounds include limiting total request body size at the proxy or web server level and monitoring memory and set per-process limits to prevent OOM conditions.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/rack/rack/commit/589127f4ac8b5cf11cf88fb0cd116ffed4d2181e GitHub, Inc.
https://github.com/rack/rack/commit/d869fed663b113b95a74ad53e1b5cae6ab31f29e GitHub, Inc.
https://github.com/rack/rack/commit/e08f78c656c9394d6737c022bde087e0f33336fd GitHub, Inc.
https://github.com/rack/rack/security/advisories/GHSA-p543-xpfm-54cp GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-400 Uncontrolled Resource Consumption GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-61770
NVD Published Date:
10/07/2025
NVD Last Modified:
10/07/2025
Source:
GitHub, Inc.