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Fencer Vulns
high 7.3

CVE-2023-40175 json

Inconsistent Interpretation of HTTP Requests in puma

published 2023-08-18 3 y ago modified 2026-09-10 1 mo ago also GHSA-68xg-gqqm-vgj8 , EUVD-2023-2224

cvss
7.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

Puma is a Ruby/Rack web server built for parallelism. Prior to versions 6.3.1 and 5.6.7, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies and zero-length Content-Length headers in a way that allowed HTTP request smuggling. Severity of this issue is highly dependent on the nature of the web site using puma is. This could be caused by either incorrect parsing of trailing fields in chunked transfer encoding bodies or by parsing of blank/zero-length Content-Length headers. Both issues have been addressed and this vulnerability has been fixed in versions 6.3.1 and 5.6.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Patch / fix

  • rubygems puma 5.6.7, 6.3.1
  • puma puma 5.6.7, 6.3.1
  • puma Debian 12 5.6.5-3+deb12u1
  • puma Debian 14, Debian 13 5.6.7-1

debian advisories DEBIAN-CVE-2023-40175

  • puma Ubuntu 24.04 LTS 5.6.5-4ubuntu2
  • puma Ubuntu Pro 20.04 LTS 3.12.4-1ubuntu2+esm1
  • puma Ubuntu Pro 22.04 LTS 5.5.2-2ubuntu2+esm1

ubuntu advisories UBUNTU-CVE-2023-40175

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • candlepin satellite 6.14 4.3.11-1.el8sat
  • mosquitto satellite capsule 6.14, satellite 6.14 2.0.17-1.el8sat
  • puppet-agent satellite capsule 6.14, satellite 6.14 7.27.0-1.el8sat
  • puppetserver satellite capsule 6.14, satellite 6.14 7.14.0-1.el8sat
  • rubygem-grpc satellite 6.14 1.58.0-1.el8sat
  • rubygem-puma satellite 6.14 6.3.1-1.el8sat
  • rubygem-sidekiq satellite 6.14 6.5.12-1.el8sat
  • candlepin-selinux satellite 6.14 4.3.11-1.el8sat

red hat advisories RHSA-2024:0797

  • rubygem-puma SLE High Availability Extension 15 SP7, SLE High Availability Extension 15 SP6, openSUSE Leap 15.6 5.6.9-150600.18.3.1
  • rubygem-puma SLE High Availability Extension 15 SP5, SLE High Availability Extension 15 SP4, SLE High Availability Extension 15 SP3 5.6.9-150000.3.18.1
  • rubygem-puma SLE High Availability Extension 15 SP5, SLE High Availability Extension 15 SP4, SLE High Availability Extension 15 SP3 +4 more 4.3.12-150000.3.12.1

suse advisories SUSE-SU-2025:03467-1SUSE-SU-2025:03466-1SUSE-SU-2023:3957-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-40175 updated cvss 7.3

rubygem-puma: HTTP request smuggling when parsing chunked transfer encoding bodies and zero-length content-length headers

  • Red Hat 3scale API Management Platform 2 3scale-amp2/zync-rhel8 Red Hat Satellite 6 tfm-rubygem-puma
    affected: no fix available
  • Red Hat Storage 3 rubygem-puma
    affected: no fix planned “Will not fix”
  • Red Hat Satellite 6.14 for RHEL 8 rubygem-puma 6.3.1-1.el8sat
    fixed: vendor fix RHSA-2024:0797
  • Red Hat Satellite 6.14 for RHEL 8 candlepin 4.3.11-1.el8sat, foreman 3.7.0.11-2.el8sat, mosquitto 2.0.17-1.el8sat, satellite 6.14.2-1.el8sat, rubygem-kafo 7.2.0-1.el8sat, puppet-agent 7.27.0-1.el8sat, +27 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.85% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
rubygems puma
<5.6.7
>=6.0.0, <6.3.1
5.6.7
6.3.1

Affected products

  • puma puma

Classification

Weakness
  • CWE-444 Inconsistent Interpretation of HTTP Requests

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.