Bug 2402175 (CVE-2025-61771)

Summary: CVE-2025-61771 rack: Rack's multipart parser buffers large non‑file fields entirely in memory, enabling DoS (memory exhaustion)
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: akostadi, amasferr, cbartlet, crizzo, dmayorov, eglynn, jcantril, jjoyce, jkoehler, jlledo, jschluet, jvasik, kaycoth, lhh, lphiri, lsvaty, mburns, mgarciac, mkudlej, mmakovy, pantinor, pgrist, rblanco, rojacob, sdawley, tjochec, tsedmik, vmugicag
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in Rack where Rack::Multipart::Parser stores non-file form fields entirely in memory without size limits. An attacker can send a multipart/form-data request with an extremely large text field, causing the server to allocate large amounts of memory which leads to a denial of service crash due to out-of-memory issue.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2025-10-07 15:01:47 UTC
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.

Comment 2 errata-xmlrpc 2025-11-03 20:11:12 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2025:19513 https://access.redhat.com/errata/RHSA-2025:19513

Comment 3 errata-xmlrpc 2025-11-03 20:18:24 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:19512 https://access.redhat.com/errata/RHSA-2025:19512

Comment 4 errata-xmlrpc 2025-11-04 11:16:20 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

Via RHSA-2025:19647 https://access.redhat.com/errata/RHSA-2025:19647

Comment 5 errata-xmlrpc 2025-11-04 17:00:46 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2025:19719 https://access.redhat.com/errata/RHSA-2025:19719

Comment 6 errata-xmlrpc 2025-11-04 19:58:27 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.6 Telecommunications Update Service

Via RHSA-2025:19734 https://access.redhat.com/errata/RHSA-2025:19734

Comment 7 errata-xmlrpc 2025-11-05 13:07:46 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

Via RHSA-2025:19800 https://access.redhat.com/errata/RHSA-2025:19800

Comment 8 errata-xmlrpc 2025-11-10 01:34:43 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

Via RHSA-2025:19948 https://access.redhat.com/errata/RHSA-2025:19948

Comment 9 errata-xmlrpc 2025-11-11 15:01:15 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:20962 https://access.redhat.com/errata/RHSA-2025:20962

Comment 10 errata-xmlrpc 2025-11-11 19:48:55 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2025:21036 https://access.redhat.com/errata/RHSA-2025:21036

Comment 12 errata-xmlrpc 2025-11-18 14:39:20 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2025:21696 https://access.redhat.com/errata/RHSA-2025:21696