CVE-2025-61771 (GCVE-0-2025-61771)

Vulnerability from cvelistv5 – Published: 2025-10-07 14:42 – Updated: 2025-10-07 17:52
VLAI
Title
Rack's multipart parser buffers large non‑file fields entirely in memory, enabling DoS (memory exhaustion)
Summary
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` 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). Attackers can send large non-file fields to trigger excessive memory usage. Impact scales with request size and concurrency, potentially leading to worker crashes or severe garbage-collection overhead. All Rack applications processing multipart form submissions are affected. Versions 2.2.19, 3.1.17, and 3.2.2 enforce a reasonable size cap for non-file fields (e.g., 2 MiB). Workarounds include restricting maximum request body size at the web-server or proxy layer (e.g., Nginx `client_max_body_size`) and validating and rejecting unusually large form fields at the application level.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-10-07 17:51 UTC
CWE
  • CWE-400 - Uncontrolled Resource Consumption
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7760 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
rack rack Affected: < 2.2.19
Affected: >= 3.1, < 3.1.17
Affected: >= 3.2, < 3.2.2
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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