HOMEVULNERABILITIESCVE-2024-21647
HIGH

CVE-2024-21647

CWE-444Published: January 8, 2024· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2024-21647 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

puma1 product(s)
puma
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/puma/puma/commit/5fc43d73b6ff193325e657a24ed76dec79133e93
PATCHhttps://github.com/puma/puma/commit/5fc43d73b6ff193325e657a24ed76dec79133e93
ADVISORYhttps://github.com/puma/puma/security/advisories/GHSA-c2f4-cvqm-65w2
ADVISORYhttps://github.com/puma/puma/security/advisories/GHSA-c2f4-cvqm-65w2

All References (5)

→
https://github.com/puma/puma/commit/5fc43d73b6ff193325e657a24ed76dec79133e93Patch
→
https://github.com/puma/puma/security/advisories/GHSA-c2f4-cvqm-65w2Vendor Advisory
→
https://github.com/puma/puma/commit/5fc43d73b6ff193325e657a24ed76dec79133e93Patch
→
https://github.com/puma/puma/security/advisories/GHSA-c2f4-cvqm-65w2Vendor Advisory
→
https://lists.debian.org/debian-lts-announce/2024/11/msg00004.html

Quick Facts

CVE IDCVE-2024-21647
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-444
CISA KEVNo
Affected1 vendor(s)
PublishedJan 8, 2024

Related CVEs (CWE-444)

CVE-2018-3907
10.0
CVE-2025-1867
10.0
CVE-2025-55315
9.9
CVE-2017-7657
9.8
CVE-2026-9170
9.8
CVE-2016-10711
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2024-21647 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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