CVE-2024-21647 MEDIUM

CVE-2024-21647: HTTP Request/Response Smuggling in puma

Vendor Puma
Product puma
Weakness CWE-444
Published January 8, 2024
Last update November 3, 2025
View on NVD All CVEs

CVSS base score

5.9/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

Puma is a web server for Ruby/Rack applications built for parallelism. Prior to version 6.4.2, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies in a way that allowed HTTP request smuggling. Fixed versions limits the size of chunk extensions. Without this limit, an attacker could cause unbounded resource (CPU, network bandwidth) consumption. This vulnerability has been fixed in versions 6.4.2 and 5.6.8.

Key dates

02Disclosure timeline

January 8, 2024 CVE published
November 3, 2025 Record updated