CVE-2025-61770 (GCVE-0-2025-61770)

Vulnerability from cvelistv5 – Published: 2025-10-07 14:30 – Updated: 2025-10-07 15:43
VLAI
Title
Rack's unbounded multipart preamble buffering enables 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` 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.
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 15:23 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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