CVE-2025-6442

EUVD-2025-19113

25.06.2025, 17:15

Ruby WEBrick read_header HTTP Request Smuggling Vulnerability. This vulnerability allows remote attackers to smuggle arbitrary HTTP requests on affected installations of Ruby WEBrick. This issue is exploitable when the product is deployed behind an HTTP proxy that fulfills specific conditions.

The specific flaw exists within the read_headers method. The issue results from the inconsistent parsing of terminators of HTTP headers. An attacker can leverage this vulnerability to smuggle arbitrary HTTP requests. Was ZDI-CAN-21876.

HTTP Request/Response Smuggling

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	5.9 MEDIUM	NETWORK	HIGH	NONE	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Base Score

CVSS 3.x

EPSS Score

Percentile: 33%

Affected Products (NVD)

Vendor	Product	Version
ruby-lang	webrick	𝑥 < 1.8.2

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

ruby-webrick

bookworm	no-dsa
forky	1.9.2-1 fixed
sid	1.9.2-2 fixed
trixie	1.9.1-1 fixed

Ubuntu Releases

Ubuntu Product

Codename

jruby

bionic	needed
focal	needed
jammy	dne
noble	not-affected
plucky	not-affected
questing	not-affected
resolute	not-affected
trusty	needed
xenial	ignored

ruby-webrick

jammy	Fixed 1.7.0-3ubuntu0.2 released
noble	Fixed 1.8.1-1ubuntu0.2 released
oracular	ignored
plucky	Fixed 1.8.1-1ubuntu1.1 released
questing	Fixed 1.9.1-1 released
resolute	Fixed 1.9.1-1 released

ruby2.3

jammy	dne
noble	dne
plucky	dne
questing	dne
resolute	dne
xenial	Fixed 2.3.1-2~ubuntu16.04.16+esm11 released

ruby2.5

bionic	Fixed 2.5.1-1ubuntu1.16+esm6 released
jammy	dne
noble	dne
plucky	dne
questing	dne
resolute	dne

ruby2.7

focal	Fixed 2.7.0-5ubuntu1.18+esm3 released
jammy	dne
noble	dne
plucky	dne
questing	dne
resolute	dne

openSUSE / SLES Releases

openSUSE Product

Release

libruby2_5-2_5

suse enterprise desktop 15 SP6	2.5.9-150000.4.46.1 fixed
suse enterprise desktop 15 SP7	2.5.9-150700.24.3.1 fixed
suse enterprise sap 15 SP3	2.5.9-150000.4.46.1 fixed
suse enterprise sap 15 SP4	2.5.9-150000.4.46.1 fixed
suse enterprise sap 15 SP5	2.5.9-150000.4.46.1 fixed
suse enterprise sap 15 SP6	2.5.9-150000.4.46.1 fixed
suse enterprise sap 15 SP7	2.5.9-150700.24.3.1 fixed
suse enterprise server 15 SP2	2.5.9-150000.4.46.1 fixed
suse enterprise server 15 SP3	2.5.9-150000.4.46.1 fixed
suse enterprise server 15 SP4	2.5.9-150000.4.46.1 fixed
suse enterprise server 15 SP5	2.5.9-150000.4.46.1 fixed
suse enterprise server 15 SP6	2.5.9-150000.4.46.1 fixed
suse enterprise server 15 SP7	2.5.9-150700.24.3.1 fixed

Amazon Linux Releases

Amazon Package

Release

ruby

Amazon Linux 2

0:2.0.0.648-36.amzn2.0.15

fixed

ruby-debuginfo

Amazon Linux 2

0:2.0.0.648-36.amzn2.0.15

fixed

ruby-devel

Amazon Linux 2

0:2.0.0.648-36.amzn2.0.15

fixed

ruby-doc

Amazon Linux 2

0:2.0.0.648-36.amzn2.0.15

fixed

ruby-irb

Amazon Linux 2

0:2.0.0.648-36.amzn2.0.15

fixed

ruby-libs

Amazon Linux 2

0:2.0.0.648-36.amzn2.0.15

fixed

ruby-tcltk

Amazon Linux 2

0:2.0.0.648-36.amzn2.0.15

fixed

ruby3.2

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-bundled-gems

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-bundled-gems-debuginfo

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-debuginfo

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-debugsource

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-default-gems

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-devel

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-doc

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-libs

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-libs-debuginfo

Amazon Linux 2023

0:3.2.8-184.amzn2023.0.2

fixed

ruby3.2-rubygem-bigdecimal

Amazon Linux 2023

0:3.1.3-184.amzn2023.0.2

fixed

ruby3.2-rubygem-bigdecimal-debuginfo

Amazon Linux 2023

0:3.1.3-184.amzn2023.0.2

fixed

ruby3.2-rubygem-bundler

Amazon Linux 2023

0:2.4.19-184.amzn2023.0.2

fixed

ruby3.2-rubygem-io-console

Amazon Linux 2023

0:0.6.0-184.amzn2023.0.2

fixed

ruby3.2-rubygem-io-console-debuginfo

Amazon Linux 2023

0:0.6.0-184.amzn2023.0.2

fixed

ruby3.2-rubygem-irb

Amazon Linux 2023

0:1.6.2-184.amzn2023.0.2

fixed

ruby3.2-rubygem-json

Amazon Linux 2023

0:2.6.3-184.amzn2023.0.2

fixed

ruby3.2-rubygem-json-debuginfo

Amazon Linux 2023

0:2.6.3-184.amzn2023.0.2

fixed

ruby3.2-rubygem-minitest

Amazon Linux 2023

0:5.25.1-184.amzn2023.0.2

fixed

ruby3.2-rubygem-power_assert

Amazon Linux 2023

0:2.0.3-184.amzn2023.0.2

fixed

ruby3.2-rubygem-psych

Amazon Linux 2023

0:5.0.1-184.amzn2023.0.2

fixed

ruby3.2-rubygem-psych-debuginfo

Amazon Linux 2023

0:5.0.1-184.amzn2023.0.2

fixed

ruby3.2-rubygem-rake

Amazon Linux 2023

0:13.0.6-184.amzn2023.0.2

fixed

ruby3.2-rubygem-rbs

Amazon Linux 2023

0:2.8.2-184.amzn2023.0.2

fixed

ruby3.2-rubygem-rbs-debuginfo

Amazon Linux 2023

0:2.8.2-184.amzn2023.0.2

fixed

ruby3.2-rubygem-rdoc

Amazon Linux 2023

0:6.5.1.1-184.amzn2023.0.2

fixed

ruby3.2-rubygem-rexml

Amazon Linux 2023

0:3.3.9-184.amzn2023.0.2

fixed

ruby3.2-rubygem-rss

Amazon Linux 2023

0:0.3.1-184.amzn2023.0.2

fixed

ruby3.2-rubygem-test-unit

Amazon Linux 2023

0:3.5.7-184.amzn2023.0.2

fixed

ruby3.2-rubygem-typeprof

Amazon Linux 2023

0:0.21.3-184.amzn2023.0.2

fixed

ruby3.2-rubygems

Amazon Linux 2023

0:3.4.19-184.amzn2023.0.2

fixed

ruby3.2-rubygems-devel

Amazon Linux 2023

0:3.4.19-184.amzn2023.0.2

fixed

rubygem-bigdecimal

Amazon Linux 2

0:1.2.0-36.amzn2.0.15

fixed

rubygem-io-console

Amazon Linux 2

0:0.4.2-36.amzn2.0.15

fixed

rubygem-json

Amazon Linux 2

0:1.7.7-36.amzn2.0.15

fixed

rubygem-minitest

Amazon Linux 2

0:4.3.2-36.amzn2.0.15

fixed

rubygem-psych

Amazon Linux 2

0:2.0.0-36.amzn2.0.15

fixed

rubygem-rake

Amazon Linux 2

0:0.9.6-36.amzn2.0.15

fixed

rubygem-rdoc

Amazon Linux 2

0:4.0.0-36.amzn2.0.15

fixed

rubygems

Amazon Linux 2

0:2.0.14.1-36.amzn2.0.15

fixed

rubygems-devel

Amazon Linux 2

0:2.0.14.1-36.amzn2.0.15

fixed

Azure Linux Releases

Azure Package

Release

ruby

Azure Linux 3.0	0:3.3.5-4.azl3 fixed
CBL-Mariner 2.0	0:3.1.7-2.cm2 fixed

rubygem-webrick

Azure Linux 3.0	0:1.8.1-2.azl3 fixed
CBL-Mariner 2.0	0:1.7.0-2.cm2 fixed

Common Weakness Enumeration

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

References

https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864

https://www.zerodayinitiative.com/advisories/ZDI-25-414/