CVE-2025-61772

HIGH EPSS 53.5%
Published Oct 7, 20258mo ago · Modified Jun 17, 20261w ago
7.5 CVSS 3.1
High
Find Similar
Published Oct 7, 2025 8mo ago
Last Modified Jun 17, 2026 1w ago

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` can accumulate unbounded data when a multipart part’s header block never terminates with the required blank line (`CRLFCRLF`). The parser keeps appending incoming bytes to memory without a size cap, allowing a remote attacker to exhaust memory and cause a denial of service (DoS). Attackers can send incomplete multipart headers to trigger high memory use, leading to process termination (OOM) or severe slowdown. The effect scales with request size limits and concurrency. All applications handling multipart uploads may be affected. Versions 2.2.19, 3.1.17, and 3.2.2 cap per-part header size (e.g., 64 KiB). As a workaround, restrict maximum request sizes at the proxy or web server layer (e.g., Nginx `client_max_body_size`).

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
53.5% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-400 Uncontrolled Resource Consumption Resource Mgmt

Affected Products 3

VendorProductVersionRange
rackrack* <2.2.19
rackrack*≥3.1.0  –  <3.1.17
rackrack*≥3.2.0  –  <3.2.2

References 4

  • github.com https://github.com/rack/rack/commit/589127f4ac8b5cf11cf88fb0cd116ffed4d2181e
    Patch
  • github.com https://github.com/rack/rack/commit/d869fed663b113b95a74ad53e1b5cae6ab31f29e
    Patch
  • github.com https://github.com/rack/rack/commit/e08f78c656c9394d6737c022bde087e0f33336fd
    Patch
  • github.com https://github.com/rack/rack/security/advisories/GHSA-wpv5-97wm-hp9c
    MitigationVendor Advisory

Remediation

  • github.com https://github.com/rack/rack/commit/589127f4ac8b5cf11cf88fb0cd116ffed4d2181e
    Patch
  • github.com https://github.com/rack/rack/commit/d869fed663b113b95a74ad53e1b5cae6ab31f29e
    Patch
  • github.com https://github.com/rack/rack/commit/e08f78c656c9394d6737c022bde087e0f33336fd
    Patch