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Fencer Intel
medium 5.4

CVE-2024-45614 json

Header normalization allows for client to clobber proxy set headers in Puma

published 2y ago modified 2mo ago also EUVD-2024-2761 , GHSA-9hf4-67fc-4vf4

cvss
5.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

Puma is a Ruby/Rack web server built for parallelism. In affected versions clients could clobber values set by intermediate proxies (such as X-Forwarded-For) by providing a underscore version of the same header (X-Forwarded_For). Any users relying on proxy set variables is affected. v6.4.3/v5.6.9 now discards any headers using underscores if the non-underscore version also exists. Effectively, allowing the proxy defined headers to always win. Users are advised to upgrade. Nginx has a underscores_in_headers configuration variable to discard these headers at the proxy level as a mitigation. Any users that are implicitly trusting the proxy defined headers for security should immediately cease doing so until upgraded to the fixed versions.

Patch / fix

  • rubygems puma 5.6.9, 6.4.3
  • puma puma 5.6.9, 6.4.3
  • puma Debian 12 5.6.5-3+deb12u1
  • puma Debian 14, Debian 13 6.4.3-1

debian advisories DEBIAN-CVE-2024-45614

  • puma Ubuntu 24.04 LTS 6.4.2-4ubuntu4.3
  • puma Ubuntu Pro 20.04 LTS 3.12.4-1ubuntu2+esm2
  • puma Ubuntu Pro 22.04 LTS 5.5.2-2ubuntu2+esm2

ubuntu advisories UBUNTU-CVE-2024-45614

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

  • 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 +2 more 4.3.12-150000.3.15.1

suse advisories SUSE-SU-2025:03467-1SUSE-SU-2025:03466-1SUSE-SU-2024:3644-1

  • rubygem-puma openSUSE Tumbleweed 6.4.3-1.5
  • rubygem-puma openSUSE Tumbleweed 6.4.3-1.3
  • rubygem-puma openSUSE Tumbleweed 6.4.3-1.1

opensuse advisories openSUSE-SU-2026:10357-1openSUSE-SU-2025:15123-1openSUSE-SU-2024:14474-1

Is CVE-2024-45614 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2024-45614 updated cvss 5.4

rubygem-puma: Header normalization allows for client to clobber proxy set headers

  • Red Hat Satellite 6 rubygem-puma
    affected: workaround, no fix available
  • Red Hat Storage 3 rubygem-puma
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 pcs, pcs-snmp Red Hat Enterprise Linux 9 pcs, pcs-snmp
    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
no
Technical impact
partial
Assessed
2y ago

Exploit prediction

0.64% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 5.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
GitHub 3.1 5.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
rubygems puma
<5.6.9
>=6.0.0, <6.4.3
5.6.9
6.4.3

Affected products

  • puma puma

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key
  • CWE-444 Inconsistent Interpretation of HTTP Requests

References

Sources

Fencer Intel 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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.