CVE-2025-61919 (GCVE-0-2025-61919)
Vulnerability from cvelistv5 – Published: 2025-10-10 19:22 – Updated: 2025-10-10 20:48
VLAI
EPSS
VEX
Title
Rack is vulnerable to a memory-exhaustion DoS through unbounded URL-encoded body parsing
Summary
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`).
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-10-10 20:48 UTC
CWE
- CWE-400 - Uncontrolled Resource Consumption
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/rack/rack/security/advisories/… | x_refsource_CONFIRM |
| https://github.com/rack/rack/commit/4e2c903991a79… | x_refsource_MISC |
| https://github.com/rack/rack/commit/cbd541e8a3d0c… | x_refsource_MISC |
| https://github.com/rack/rack/commit/e179614c4a653… | x_refsource_MISC |
Impacted products
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Nomenclature
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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